724632561 has 21 divisors (see below), whose sum is σ = 1087542651. Its totient is φ = 482603832.

The previous prime is 724632551. The next prime is 724632577. The reversal of 724632561 is 165236427.

The square root of 724632561 is 26919.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 623750625 + 100881936 = 24975^2 + 10044^2 .

It is a de Polignac number, because none of the positive numbers 2^k-724632561 is a prime.

It is a super-2 number, since 2×724632561² = 1050184696922837442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (724632551) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 726315 + ... + 727311.

Almost surely, 2^724632561 is an apocalyptic number.

724632561 is the 26919-th square number.

724632561 is the 13460-th centered octagonal number.

It is an amenable number.

724632561 is a deficient number, since it is larger than the sum of its proper divisors (362910090).

724632561 is an frugal number, since it uses more digits than its factorization.

724632561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2012 (or 1000 counting only the distinct ones).

The product of its digits is 60480, while the sum is 36.

The cubic root of 724632561 is about 898.1990987979.

Multiplying 724632561 by its sum of digits (36), we get a square (26086772196 = 161514²).

Adding to 724632561 its reverse (165236427), we get a palindrome (889868988).

The spelling of 724632561 in words is "seven hundred twenty-four million, six hundred thirty-two thousand, five hundred sixty-one".