1231211100 has 72 divisors (see below), whose sum is σ = 4071211648. Its totient is φ = 281419200.

The previous prime is 1231211087. The next prime is 1231211119. The reversal of 1231211100 is 11121321.

It is a Harshad number since it is a multiple of its sum of digits (12).

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, 291046 + ... + 295245.

Almost surely, 2^1231211100 is an apocalyptic number.

1231211100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231211100 is an abundant number, since it is smaller than the sum of its proper divisors (2840000548).

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

1231211100 is a wasteful number, since it uses less digits than its factorization.

1231211100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586315 (or 586308 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 12.

The square root of 1231211100 is about 35088.6178126184. The cubic root of 1231211100 is about 1071.7928135553.

Adding to 1231211100 its reverse (11121321), we get a palindrome (1242332421).

The spelling of 1231211100 in words is "one billion, two hundred thirty-one million, two hundred eleven thousand, one hundred".