1213172056 has 16 divisors (see below), whose sum is σ = 2280801600. Its totient is φ = 604958304.

The previous prime is 1213172047. The next prime is 1213172117. The reversal of 1213172056 is 6502713121.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200296 + ... + 206263.

It is an arithmetic number, because the mean of its divisors is an integer number (142550100).

Almost surely, 2^1213172056 is an apocalyptic number.

It is an amenable number.

1213172056 is a deficient number, since it is larger than the sum of its proper divisors (1067629544).

1213172056 is a wasteful number, since it uses less digits than its factorization.

1213172056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406938 (or 406934 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 1213172056 is about 34830.6195178897. The cubic root of 1213172056 is about 1066.5325950413.

Adding to 1213172056 its reverse (6502713121), we get a palindrome (7715885177).

The spelling of 1213172056 in words is "one billion, two hundred thirteen million, one hundred seventy-two thousand, fifty-six".