12691720 has 32 divisors (see below), whose sum is σ = 28730520. Its totient is φ = 5045760.

The previous prime is 12691717. The next prime is 12691733. The reversal of 12691720 is 2719621.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2490084 + 10201636 = 1578^2 + 3194^2 .

It is a super-2 number, since 2×12691720² = 322159513116800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6364 + ... + 8116.

Almost surely, 2^12691720 is an apocalyptic number.

12691720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12691720 is an abundant number, since it is smaller than the sum of its proper divisors (16038800).

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

12691720 is a wasteful number, since it uses less digits than its factorization.

12691720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1945 (or 1941 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 12691720 is about 3562.5440348156. The cubic root of 12691720 is about 233.2599406363.

The spelling of 12691720 in words is "twelve million, six hundred ninety-one thousand, seven hundred twenty".