1211751090 has 288 divisors, whose sum is σ = 3775165056. Its totient is φ = 277136640.

The previous prime is 1211751089. The next prime is 1211751091. The reversal of 1211751090 is 901571121.

It is an interprime number because it is at equal distance from previous prime (1211751089) and next prime (1211751091).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1211751091) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 16599294 + ... + 16599366.

It is an arithmetic number, because the mean of its divisors is an integer number (13108212).

Almost surely, 2^1211751090 is an apocalyptic number.

1211751090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211751090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1887582528).

1211751090 is an abundant number, since it is smaller than the sum of its proper divisors (2563413966).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211751090 is an equidigital number, since it uses as much as digits as its factorization.

1211751090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 630, while the sum is 27.

The square root of 1211751090 is about 34810.2153110262. The cubic root of 1211751090 is about 1066.1160290568.

It can be divided in two parts, 121175 and 1090, that added together give a triangular number (122265 = T₄₉₄).

The spelling of 1211751090 in words is "one billion, two hundred eleven million, seven hundred fifty-one thousand, ninety".