55697940 has 36 divisors (see below), whose sum is σ = 168950964. Its totient is φ = 14852736.

The previous prime is 55697903. The next prime is 55697959. The reversal of 55697940 is 4979655.

It is a happy number.

55697940 is a `hidden beast` number, since 556 + 9 + 7 + 94 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18096516 + 37601424 = 4254^2 + 6132^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 154537 + ... + 154896.

Almost surely, 2^55697940 is an apocalyptic number.

It is an amenable number.

55697940 is an abundant number, since it is smaller than the sum of its proper divisors (113253024).

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

55697940 is a wasteful number, since it uses less digits than its factorization.

55697940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309448 (or 309443 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The square root of 55697940 is about 7463.1052518372. The cubic root of 55697940 is about 381.8971150972.

The spelling of 55697940 in words is "fifty-five million, six hundred ninety-seven thousand, nine hundred forty".