721642984 has 16 divisors (see below), whose sum is σ = 1353636900. Its totient is φ = 360673152.

The previous prime is 721642981. The next prime is 721643003. The reversal of 721642984 is 489246127.

It can be written as a sum of positive squares in 2 ways, for example, as 628906084 + 92736900 = 25078^2 + 9630^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 721642984.

It is not an unprimeable number, because it can be changed into a prime (721642981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3702 + ... + 38170.

Almost surely, 2^721642984 is an apocalyptic number.

It is an amenable number.

721642984 is a deficient number, since it is larger than the sum of its proper divisors (631993916).

721642984 is a wasteful number, since it uses less digits than its factorization.

721642984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37092 (or 37088 counting only the distinct ones).

The product of its digits is 193536, while the sum is 43.

The square root of 721642984 is about 26863.4134837701. The cubic root of 721642984 is about 896.9621792079.

The spelling of 721642984 in words is "seven hundred twenty-one million, six hundred forty-two thousand, nine hundred eighty-four".