55451640 has 32 divisors (see below), whose sum is σ = 166355280. Its totient is φ = 14787072.

The previous prime is 55451609. The next prime is 55451647. The reversal of 55451640 is 4615455.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 55451598 and 55451607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55451647) 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, 230929 + ... + 231168.

Almost surely, 2^55451640 is an apocalyptic number.

It is an amenable number.

55451640 is an abundant number, since it is smaller than the sum of its proper divisors (110903640).

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

55451640 is a wasteful number, since it uses less digits than its factorization.

55451640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462111 (or 462107 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 55451640 is about 7446.5857948459. The cubic root of 55451640 is about 381.3333584636. Note that the first 4 decimals are identical.

The spelling of 55451640 in words is "fifty-five million, four hundred fifty-one thousand, six hundred forty".