12920581 has 2 divisors, whose sum is σ = 12920582. Its totient is φ = 12920580.

The previous prime is 12920563. The next prime is 12920647. The reversal of 12920581 is 18502921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11902500 + 1018081 = 3450^2 + 1009^2 .

It is a cyclic number.

It is not a de Polignac number, because 12920581 - 2¹⁵ = 12887813 is a prime.

It is a super-2 number, since 2×12920581² = 333882826755122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12920381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6460290 + 6460291.

It is an arithmetic number, because the mean of its divisors is an integer number (6460291).

Almost surely, 2^12920581 is an apocalyptic number.

It is an amenable number.

12920581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12920581 is an equidigital number, since it uses as much as digits as its factorization.

12920581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 12920581 is about 3594.5209694756. The cubic root of 12920581 is about 234.6536682047.

It can be divided in two parts, 129205 and 81, that added together give a triangular number (129286 = T₅₀₈).

The spelling of 12920581 in words is "twelve million, nine hundred twenty thousand, five hundred eighty-one".