55451840 has 56 divisors (see below), whose sum is σ = 133045200. Its totient is φ = 22012928.

The previous prime is 55451819. The next prime is 55451843. The reversal of 55451840 is 4815455.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 55451797 and 55451806.

It is not an unprimeable number, because it can be changed into a prime (55451843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47099 + ... + 48261.

Almost surely, 2^55451840 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 55451840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66522600).

55451840 is an abundant number, since it is smaller than the sum of its proper divisors (77593360).

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

55451840 is a wasteful number, since it uses less digits than its factorization.

55451840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1329 (or 1319 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 32.

The square root of 55451840 is about 7446.5992238068. The cubic root of 55451840 is about 381.3338169206. Note that the first 3 decimals are identical.

The spelling of 55451840 in words is "fifty-five million, four hundred fifty-one thousand, eight hundred forty".