721747625 has 16 divisors (see below), whose sum is σ = 905438352. Its totient is φ = 574387200.

The previous prime is 721747591. The next prime is 721747627. The reversal of 721747625 is 526747127.

It can be written as a sum of positive squares in 8 ways, for example, as 165353881 + 556393744 = 12859^2 + 23588^2 .

It is a de Polignac number, because none of the positive numbers 2^k-721747625 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721747627) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9167 + ... + 39083.

It is an arithmetic number, because the mean of its divisors is an integer number (56589897).

Almost surely, 2^721747625 is an apocalyptic number.

It is an amenable number.

721747625 is a deficient number, since it is larger than the sum of its proper divisors (183690727).

721747625 is a wasteful number, since it uses less digits than its factorization.

721747625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30125 (or 30115 counting only the distinct ones).

The product of its digits is 164640, while the sum is 41.

The square root of 721747625 is about 26865.3610621559. The cubic root of 721747625 is about 897.0055314311.

The spelling of 721747625 in words is "seven hundred twenty-one million, seven hundred forty-seven thousand, six hundred twenty-five".