53721521 has 16 divisors (see below), whose sum is σ = 64606080. Its totient is φ = 43701120.

The previous prime is 53721497. The next prime is 53721527. The reversal of 53721521 is 12512735.

It is a cyclic number.

It is not a de Polignac number, because 53721521 - 2¹⁰ = 53720497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (53721527) 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, 8090 + ... + 13148.

It is an arithmetic number, because the mean of its divisors is an integer number (4037880).

Almost surely, 2^53721521 is an apocalyptic number.

It is an amenable number.

53721521 is a deficient number, since it is larger than the sum of its proper divisors (10884559).

53721521 is a wasteful number, since it uses less digits than its factorization.

53721521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5144.

The product of its digits is 2100, while the sum is 26.

The square root of 53721521 is about 7329.4966402885. The cubic root of 53721521 is about 377.3254512255.

The spelling of 53721521 in words is "fifty-three million, seven hundred twenty-one thousand, five hundred twenty-one".