55997661 has 8 divisors (see below), whose sum is σ = 75139744. Its totient is φ = 37093680.

The previous prime is 55997659. The next prime is 55997671. The reversal of 55997661 is 16679955.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 55997661 - 2¹ = 55997659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55997661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55997611) 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, 58975 + ... + 59916.

It is an arithmetic number, because the mean of its divisors is an integer number (9392468).

Almost surely, 2^55997661 is an apocalyptic number.

It is an amenable number.

55997661 is a deficient number, since it is larger than the sum of its proper divisors (19142083).

55997661 is a wasteful number, since it uses less digits than its factorization.

55997661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119051.

The product of its digits is 510300, while the sum is 48.

The square root of 55997661 is about 7483.1584909048. The cubic root of 55997661 is about 382.5809098779.

The spelling of 55997661 in words is "fifty-five million, nine hundred ninety-seven thousand, six hundred sixty-one".