40625721 has 12 divisors (see below), whose sum is σ = 58778980. Its totient is φ = 27038880.

The previous prime is 40625713. The next prime is 40625737. The reversal of 40625721 is 12752604.

40625721 is a `hidden beast` number, since 406 + 257 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 27405225 + 13220496 = 5235^2 + 3636^2 .

It is not a de Polignac number, because 40625721 - 2³ = 40625713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40625701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2535 + ... + 9363.

Almost surely, 2^40625721 is an apocalyptic number.

It is an amenable number.

40625721 is a deficient number, since it is larger than the sum of its proper divisors (18153259).

40625721 is a wasteful number, since it uses less digits than its factorization.

40625721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7496 (or 7493 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 40625721 is about 6373.8309516334. The cubic root of 40625721 is about 343.7692504481.

The spelling of 40625721 in words is "forty million, six hundred twenty-five thousand, seven hundred twenty-one".