55820978791 has 2 divisors, whose sum is σ = 55820978792. Its totient is φ = 55820978790.

The previous prime is 55820978761. The next prime is 55820978797. The reversal of 55820978791 is 19787902855.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55820978791 - 2¹⁵ = 55820946023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55820978797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27910489395 + 27910489396.

It is an arithmetic number, because the mean of its divisors is an integer number (27910489396).

Almost surely, 2^55820978791 is an apocalyptic number.

55820978791 is a deficient number, since it is larger than the sum of its proper divisors (1).

55820978791 is an equidigital number, since it uses as much as digits as its factorization.

55820978791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12700800, while the sum is 61.

The spelling of 55820978791 in words is "fifty-five billion, eight hundred twenty million, nine hundred seventy-eight thousand, seven hundred ninety-one".