53121640 has 128 divisors (see below), whose sum is σ = 144789120. Its totient is φ = 17280000.

The previous prime is 53121637. The next prime is 53121659. The reversal of 53121640 is 4612135.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 211515 + ... + 211765.

It is an arithmetic number, because the mean of its divisors is an integer number (1131165).

Almost surely, 2^53121640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 53121640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72394560).

53121640 is an abundant number, since it is smaller than the sum of its proper divisors (91667480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

53121640 is a wasteful number, since it uses less digits than its factorization.

53121640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 53121640 is about 7288.4593708136. The cubic root of 53121640 is about 375.9157235291.

Adding to 53121640 its reverse (4612135), we get a palindrome (57733775).

The spelling of 53121640 in words is "fifty-three million, one hundred twenty-one thousand, six hundred forty".