55978861 has 4 divisors (see below), whose sum is σ = 56011392. Its totient is φ = 55946332.

The previous prime is 55978859. The next prime is 55978873. The reversal of 55978861 is 16887955.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 55978861 - 2¹ = 55978859 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55978061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13531 + ... + 17176.

It is an arithmetic number, because the mean of its divisors is an integer number (14002848).

Almost surely, 2^55978861 is an apocalyptic number.

It is an amenable number.

55978861 is a deficient number, since it is larger than the sum of its proper divisors (32531).

55978861 is a wasteful number, since it uses less digits than its factorization.

55978861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32530.

The product of its digits is 604800, while the sum is 49.

The square root of 55978861 is about 7481.9022313847. The cubic root of 55978861 is about 382.5380906718.

The spelling of 55978861 in words is "fifty-five million, nine hundred seventy-eight thousand, eight hundred sixty-one".