1213031100 has 36 divisors (see below), whose sum is σ = 3509704184. Its totient is φ = 323474880.

The previous prime is 1213031077. The next prime is 1213031101. The reversal of 1213031100 is 11303121.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213031101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2021419 + ... + 2022018.

Almost surely, 2^1213031100 is an apocalyptic number.

1213031100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213031100 is an abundant number, since it is smaller than the sum of its proper divisors (2296673084).

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

1213031100 is a wasteful number, since it uses less digits than its factorization.

1213031100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4043454 (or 4043447 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 1213031100 is about 34828.5960096011. The cubic root of 1213031100 is about 1066.4912873553.

Adding to 1213031100 its reverse (11303121), we get a palindrome (1224334221).

The spelling of 1213031100 in words is "one billion, two hundred thirteen million, thirty-one thousand, one hundred".