55903400721 has 99 divisors (see below), whose sum is σ = 98251991721. Its totient is φ = 31714981704.

The previous prime is 55903400681. The next prime is 55903400809. The reversal of 55903400721 is 12700430955.

The square root of 55903400721 is 236439.

It is a perfect power (a square), and thus also a powerful number.

55903400721 is a `hidden beast` number, since 5 + 590 + 3 + 40 + 0 + 7 + 21 = 666.

It is not a de Polignac number, because 55903400721 - 2²¹ = 55901303569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55903401721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 98 ways as a sum of consecutive naturals, for example, 402182670 + ... + 402182808.

Almost surely, 2^55903400721 is an apocalyptic number.

55903400721 is the 236439-th square number.

55903400721 is the 118220-th centered octagonal number.

It is an amenable number.

55903400721 is a deficient number, since it is larger than the sum of its proper divisors (42348591000).

55903400721 is an frugal number, since it uses more digits than its factorization.

55903400721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

Multiplying 55903400721 by its sum of digits (36), we get a square (2012522425956 = 1418634²).

The spelling of 55903400721 in words is "fifty-five billion, nine hundred three million, four hundred thousand, seven hundred twenty-one".