1211172690 has 192 divisors, whose sum is σ = 3704762880. Its totient is φ = 251112960.

The previous prime is 1211172673. The next prime is 1211172691. The reversal of 1211172690 is 962711121.

It is a super-2 number, since 2×1211172690² = 2933878570003672200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (1211172691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1165191 + ... + 1166229.

It is an arithmetic number, because the mean of its divisors is an integer number (19295640).

Almost surely, 2^1211172690 is an apocalyptic number.

1211172690 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 1211172690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1852381440).

1211172690 is an abundant number, since it is smaller than the sum of its proper divisors (2493590190).

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

1211172690 is a wasteful number, since it uses less digits than its factorization.

1211172690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1137 (or 1130 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 30.

The square root of 1211172690 is about 34801.9064132987. The cubic root of 1211172690 is about 1065.9463738486.

The spelling of 1211172690 in words is "one billion, two hundred eleven million, one hundred seventy-two thousand, six hundred ninety".