1211136550 has 48 divisors (see below), whose sum is σ = 2430156960. Its totient is φ = 446423040.

The previous prime is 1211136547. The next prime is 1211136571. The reversal of 1211136550 is 556311121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a zygodrome in base 5.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 498639 + ... + 501061.

It is an arithmetic number, because the mean of its divisors is an integer number (50628270).

Almost surely, 2^1211136550 is an apocalyptic number.

1211136550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1211136550 is an abundant number, since it is smaller than the sum of its proper divisors (1219020410).

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

1211136550 is a wasteful number, since it uses less digits than its factorization.

1211136550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3217 (or 3212 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 1211136550 is about 34801.3871849959. The cubic root of 1211136550 is about 1065.9357715386.

Adding to 1211136550 its reverse (556311121), we get a palindrome (1767447671).

The spelling of 1211136550 in words is "one billion, two hundred eleven million, one hundred thirty-six thousand, five hundred fifty".