40628721 has 16 divisors (see below), whose sum is σ = 62000000. Its totient is φ = 23182848.

The previous prime is 40628717. The next prime is 40628723. The reversal of 40628721 is 12782604.

It is not a de Polignac number, because 40628721 - 2² = 40628717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (40628723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25455 + ... + 27003.

It is an arithmetic number, because the mean of its divisors is an integer number (3875000).

Almost surely, 2^40628721 is an apocalyptic number.

It is an amenable number.

40628721 is a deficient number, since it is larger than the sum of its proper divisors (21371279).

40628721 is a wasteful number, since it uses less digits than its factorization.

40628721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2808.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 40628721 is about 6374.0662845628. The cubic root of 40628721 is about 343.7777121020. Note that the first 4 decimals are identical.

The spelling of 40628721 in words is "forty million, six hundred twenty-eight thousand, seven hundred twenty-one".