721500039 has 18 divisors (see below), whose sum is σ = 1128502440. Its totient is φ = 443999088.

The previous prime is 721500023. The next prime is 721500047. The reversal of 721500039 is 930005127.

It is not a de Polignac number, because 721500039 - 2⁴ = 721500023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 721499985 and 721500021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721500239) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 235659 + ... + 238700.

It is an arithmetic number, because the mean of its divisors is an integer number (62694580).

Almost surely, 2^721500039 is an apocalyptic number.

721500039 is a deficient number, since it is larger than the sum of its proper divisors (407002401).

721500039 is a wasteful number, since it uses less digits than its factorization.

721500039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474391 (or 474375 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 721500039 is about 26860.7527630928. The cubic root of 721500039 is about 896.9029510631.

The spelling of 721500039 in words is "seven hundred twenty-one million, five hundred thousand, thirty-nine".