55640780 has 24 divisors (see below), whose sum is σ = 125834352. Its totient is φ = 20544192.

The previous prime is 55640773. The next prime is 55640789. The reversal of 55640780 is 8704655.

It is a self number, because there is not a number n which added to its sum of digits gives 55640780.

It is not an unprimeable number, because it can be changed into a prime (55640789) 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, 106742 + ... + 107261.

It is an arithmetic number, because the mean of its divisors is an integer number (5243098).

Almost surely, 2^55640780 is an apocalyptic number.

It is an amenable number.

55640780 is an abundant number, since it is smaller than the sum of its proper divisors (70193572).

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

55640780 is a wasteful number, since it uses less digits than its factorization.

55640780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214025 (or 214023 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 35.

The square root of 55640780 is about 7459.2747636751. The cubic root of 55640780 is about 381.7664297686.

The spelling of 55640780 in words is "fifty-five million, six hundred forty thousand, seven hundred eighty".