721403998 has 16 divisors (see below), whose sum is σ = 1237762944. Its totient is φ = 308905560.

The previous prime is 721403983. The next prime is 721404049. The reversal of 721403998 is 899304127.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5088 + ... + 38323.

It is an arithmetic number, because the mean of its divisors is an integer number (77360184).

Almost surely, 2^721403998 is an apocalyptic number.

721403998 is a deficient number, since it is larger than the sum of its proper divisors (516358946).

721403998 is a wasteful number, since it uses less digits than its factorization.

721403998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44607.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 721403998 is about 26858.9649465500. The cubic root of 721403998 is about 896.8631528307.

The spelling of 721403998 in words is "seven hundred twenty-one million, four hundred three thousand, nine hundred ninety-eight".