6402580981 has 2 divisors, whose sum is σ = 6402580982. Its totient is φ = 6402580980.

The previous prime is 6402580949. The next prime is 6402580999. The reversal of 6402580981 is 1890852046.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5572622500 + 829958481 = 74650^2 + 28809^2 .

It is a cyclic number.

It is not a de Polignac number, because 6402580981 - 2⁵ = 6402580949 is a prime.

It is a super-2 number, since 2×6402580981² = 81986086436525844722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6402580931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3201290490 + 3201290491.

It is an arithmetic number, because the mean of its divisors is an integer number (3201290491).

Almost surely, 2^6402580981 is an apocalyptic number.

It is an amenable number.

6402580981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6402580981 is an equidigital number, since it uses as much as digits as its factorization.

6402580981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 6402580981 is about 80016.1295052441. The cubic root of 6402580981 is about 1856.8850801648.

The spelling of 6402580981 in words is "six billion, four hundred two million, five hundred eighty thousand, nine hundred eighty-one".