55420440391 has 2 divisors, whose sum is σ = 55420440392. Its totient is φ = 55420440390.

The previous prime is 55420440389. The next prime is 55420440431. The reversal of 55420440391 is 19304402455.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55420440391 - 2¹ = 55420440389 is a prime.

Together with 55420440389, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 55420440391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55421440391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27710220195 + 27710220196.

It is an arithmetic number, because the mean of its divisors is an integer number (27710220196).

Almost surely, 2^55420440391 is an apocalyptic number.

55420440391 is a deficient number, since it is larger than the sum of its proper divisors (1).

55420440391 is an equidigital number, since it uses as much as digits as its factorization.

55420440391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 37.

It can be divided in two parts, 554204 and 40391, that added together give a triangular number (594595 = T₁₀₉₀).

The spelling of 55420440391 in words is "fifty-five billion, four hundred twenty million, four hundred forty thousand, three hundred ninety-one".