12920557 has 8 divisors (see below), whose sum is σ = 13999160. Its totient is φ = 11924640.

The previous prime is 12920507. The next prime is 12920563. The reversal of 12920557 is 75502921.

It can be written as a sum of positive squares in 4 ways, for example, as 1990921 + 10929636 = 1411^2 + 3306^2 .

It is not a de Polignac number, because 12920557 - 2⁷ = 12920429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12920507) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 744 + ... + 5137.

It is an arithmetic number, because the mean of its divisors is an integer number (1749895).

Almost surely, 2^12920557 is an apocalyptic number.

It is an amenable number.

12920557 is a deficient number, since it is larger than the sum of its proper divisors (1078603).

12920557 is an frugal number, since it uses more digits than its factorization.

12920557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5920 (or 5894 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 12920557 is about 3594.5176310598. The cubic root of 12920557 is about 234.6535229148.

The spelling of 12920557 in words is "twelve million, nine hundred twenty thousand, five hundred fifty-seven".