55640040 has 64 divisors (see below), whose sum is σ = 172316160. Its totient is φ = 14357760.

The previous prime is 55640033. The next prime is 55640047. The reversal of 55640040 is 4004655.

It is an interprime number because it is at equal distance from previous prime (55640033) and next prime (55640047).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (55640047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3759 + ... + 11198.

It is an arithmetic number, because the mean of its divisors is an integer number (2692440).

Almost surely, 2^55640040 is an apocalyptic number.

It is an amenable number.

55640040 is an abundant number, since it is smaller than the sum of its proper divisors (116676120).

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

55640040 is a wasteful number, since it uses less digits than its factorization.

55640040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15002 (or 14998 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 55640040 is about 7459.2251608327. The cubic root of 55640040 is about 381.7647373144.

Adding to 55640040 its reverse (4004655), we get a palindrome (59644695).

The spelling of 55640040 in words is "fifty-five million, six hundred forty thousand, forty".