53121664 has 16 divisors (see below), whose sum is σ = 105828570. Its totient is φ = 26560768.

The previous prime is 53121661. The next prime is 53121671. The reversal of 53121664 is 46612135.

It can be written as a sum of positive squares in only one way, i.e., 51955264 + 1166400 = 7208^2 + 1080^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×53121664² = 5643822372257792, which contains 22 as substring.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (53121661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 207379 + ... + 207634.

Almost surely, 2^53121664 is an apocalyptic number.

It is an amenable number.

53121664 is a deficient number, since it is larger than the sum of its proper divisors (52706906).

53121664 is an equidigital number, since it uses as much as digits as its factorization.

53121664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415027 (or 415015 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 53121664 is about 7288.4610172519. The cubic root of 53121664 is about 375.9157801412.

Adding to 53121664 its reverse (46612135), we get a palindrome (99733799).

It can be divided in two parts, 5312166 and 4, that added together give a triangular number (5312170 = T₃₂₅₉).

The spelling of 53121664 in words is "fifty-three million, one hundred twenty-one thousand, six hundred sixty-four".