1213890256 has 20 divisors (see below), whose sum is σ = 2364912004. Its totient is φ = 603590400.

The previous prime is 1213890247. The next prime is 1213890269. The reversal of 1213890256 is 6520983121.

It can be written as a sum of positive squares in 2 ways, for example, as 565678656 + 648211600 = 23784^2 + 25460^2 .

It is a super-2 number, since 2×1213890256² = 2947059107223491072, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 206685 + ... + 212476.

Almost surely, 2^1213890256 is an apocalyptic number.

1213890256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1213890256 is a deficient number, since it is larger than the sum of its proper divisors (1151021748).

1213890256 is a wasteful number, since it uses less digits than its factorization.

1213890256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419350 (or 419344 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 1213890256 is about 34840.9278866106. The cubic root of 1213890256 is about 1066.7430165835.

The spelling of 1213890256 in words is "one billion, two hundred thirteen million, eight hundred ninety thousand, two hundred fifty-six".