660720724 has 12 divisors (see below), whose sum is σ = 1206533664. Its totient is φ = 315996824.

The previous prime is 660720721. The next prime is 660720727. The reversal of 660720724 is 427027066.

It is an interprime number because it is at equal distance from previous prime (660720721) and next prime (660720727).

It is a self number, because there is not a number n which added to its sum of digits gives 660720724.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660720721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3590782 + ... + 3590965.

It is an arithmetic number, because the mean of its divisors is an integer number (100544472).

Almost surely, 2^660720724 is an apocalyptic number.

It is an amenable number.

660720724 is a deficient number, since it is larger than the sum of its proper divisors (545812940).

660720724 is a wasteful number, since it uses less digits than its factorization.

660720724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7181774 (or 7181772 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 34.

The square root of 660720724 is about 25704.4884018336. The cubic root of 660720724 is about 870.9755753781.

The spelling of 660720724 in words is "six hundred sixty million, seven hundred twenty thousand, seven hundred twenty-four".