53168721 has 16 divisors (see below), whose sum is σ = 72839424. Its totient is φ = 34485264.

The previous prime is 53168719. The next prime is 53168729. The reversal of 53168721 is 12786135.

It is not a de Polignac number, because 53168721 - 2¹ = 53168719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (53168729) 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, 15090 + ... + 18276.

It is an arithmetic number, because the mean of its divisors is an integer number (4552464).

Almost surely, 2^53168721 is an apocalyptic number.

It is an amenable number.

53168721 is a deficient number, since it is larger than the sum of its proper divisors (19670703).

53168721 is a wasteful number, since it uses less digits than its factorization.

53168721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3340.

The product of its digits is 10080, while the sum is 33.

The square root of 53168721 is about 7291.6884875864. The cubic root of 53168721 is about 376.0267470976.

The spelling of 53168721 in words is "fifty-three million, one hundred sixty-eight thousand, seven hundred twenty-one".