721973420 has 48 divisors (see below), whose sum is σ = 1765447488. Its totient is φ = 242860800.

The previous prime is 721973411. The next prime is 721973437. The reversal of 721973420 is 24379127.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41231 + ... + 56070.

It is an arithmetic number, because the mean of its divisors is an integer number (36780156).

Almost surely, 2^721973420 is an apocalyptic number.

721973420 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

721973420 is an abundant number, since it is smaller than the sum of its proper divisors (1043474068).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721973420 is a wasteful number, since it uses less digits than its factorization.

721973420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97370 (or 97368 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 721973420 is about 26869.5630779512. The cubic root of 721973420 is about 897.0990628537.

The spelling of 721973420 in words is "seven hundred twenty-one million, nine hundred seventy-three thousand, four hundred twenty".