721555525 has 24 divisors (see below), whose sum is σ = 929940480. Its totient is φ = 554715840.

The previous prime is 721555487. The next prime is 721555559. The reversal of 721555525 is 525555127.

It is not a de Polignac number, because 721555525 - 2⁹ = 721555013 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 159444 + ... + 163906.

It is an arithmetic number, because the mean of its divisors is an integer number (38747520).

Almost surely, 2^721555525 is an apocalyptic number.

It is an amenable number.

721555525 is a deficient number, since it is larger than the sum of its proper divisors (208384955).

721555525 is a wasteful number, since it uses less digits than its factorization.

721555525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4725 (or 4720 counting only the distinct ones).

The product of its digits is 87500, while the sum is 37.

The square root of 721555525 is about 26861.7855884526. The cubic root of 721555525 is about 896.9259421829.

The spelling of 721555525 in words is "seven hundred twenty-one million, five hundred fifty-five thousand, five hundred twenty-five".