906725721 has 12 divisors (see below), whose sum is σ = 1328865776. Its totient is φ = 549530520.

The previous prime is 906725689. The next prime is 906725759. The reversal of 906725721 is 127527609.

It is not a de Polignac number, because 906725721 - 2⁵ = 906725689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 906725721.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1248571 + ... + 1249296.

Almost surely, 2^906725721 is an apocalyptic number.

It is an amenable number.

906725721 is a deficient number, since it is larger than the sum of its proper divisors (422140055).

906725721 is a wasteful number, since it uses less digits than its factorization.

906725721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2497892 (or 2497881 counting only the distinct ones).

The product of its (nonzero) digits is 52920, while the sum is 39.

The square root of 906725721 is about 30111.8867060834. The cubic root of 906725721 is about 967.8884599442. Note that the first 3 decimals are identical.

It can be divided in two parts, 906 and 725721, that added together give a palindrome (726627).

The spelling of 906725721 in words is "nine hundred six million, seven hundred twenty-five thousand, seven hundred twenty-one".