52661721 has 12 divisors (see below), whose sum is σ = 81679632. Its totient is φ = 30092328.

The previous prime is 52661683. The next prime is 52661731. The reversal of 52661721 is 12716625.

It is not a de Polignac number, because 52661721 - 2¹⁸ = 52399577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (52661731) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 178975 + ... + 179268.

It is an arithmetic number, because the mean of its divisors is an integer number (6806636).

Almost surely, 2^52661721 is an apocalyptic number.

It is an amenable number.

52661721 is a deficient number, since it is larger than the sum of its proper divisors (29017911).

52661721 is a wasteful number, since it uses less digits than its factorization.

52661721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358260 (or 358253 counting only the distinct ones).

The product of its digits is 5040, while the sum is 30.

The square root of 52661721 is about 7256.8396013692. The cubic root of 52661721 is about 374.8277039608.

The spelling of 52661721 in words is "fifty-two million, six hundred sixty-one thousand, seven hundred twenty-one".