6402581 has 2 divisors, whose sum is σ = 6402582. Its totient is φ = 6402580.

The previous prime is 6402577. The next prime is 6402593. The reversal of 6402581 is 1852046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6400900 + 1681 = 2530^2 + 41^2 .

It is a cyclic number.

It is not a de Polignac number, because 6402581 - 2² = 6402577 is a prime.

It is a super-2 number, since 2×6402581² = 81986086923122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6402581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6402541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3201290 + 3201291.

It is an arithmetic number, because the mean of its divisors is an integer number (3201291).

Almost surely, 2^6402581 is an apocalyptic number.

It is an amenable number.

6402581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6402581 is an equidigital number, since it uses as much as digits as its factorization.

6402581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 6402581 is about 2530.3321916302. The cubic root of 6402581 is about 185.6885082002.

The spelling of 6402581 in words is "six million, four hundred two thousand, five hundred eighty-one".