1212855997 has 12 divisors (see below), whose sum is σ = 1257630528. Its totient is φ = 1169623800.

The previous prime is 1212855991. The next prime is 1212856031. The reversal of 1212855997 is 7995582121.

It is a de Polignac number, because none of the positive numbers 2^k-1212855997 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1212855997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212855991) 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, 292972 + ... + 297082.

It is an arithmetic number, because the mean of its divisors is an integer number (104802544).

Almost surely, 2^1212855997 is an apocalyptic number.

It is an amenable number.

1212855997 is a deficient number, since it is larger than the sum of its proper divisors (44774531).

1212855997 is an equidigital number, since it uses as much as digits as its factorization.

1212855997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4480 (or 4449 counting only the distinct ones).

The product of its digits is 453600, while the sum is 49.

The square root of 1212855997 is about 34826.0821368123. The cubic root of 1212855997 is about 1066.4399683055.

The spelling of 1212855997 in words is "one billion, two hundred twelve million, eight hundred fifty-five thousand, nine hundred ninety-seven".