55661817 has 16 divisors (see below), whose sum is σ = 80115840. Its totient is φ = 34269312.

The previous prime is 55661813. The next prime is 55661861. The reversal of 55661817 is 71816655.

It is not a de Polignac number, because 55661817 - 2² = 55661813 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55661813) 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, 11908 + ... + 15909.

It is an arithmetic number, because the mean of its divisors is an integer number (5007240).

Almost surely, 2^55661817 is an apocalyptic number.

It is an amenable number.

55661817 is a deficient number, since it is larger than the sum of its proper divisors (24454023).

55661817 is a wasteful number, since it uses less digits than its factorization.

55661817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27872.

The product of its digits is 50400, while the sum is 39.

The square root of 55661817 is about 7460.6847540960. The cubic root of 55661817 is about 381.8145372204.

The spelling of 55661817 in words is "fifty-five million, six hundred sixty-one thousand, eight hundred seventeen".