55770391 has 2 divisors, whose sum is σ = 55770392. Its totient is φ = 55770390.

The previous prime is 55770389. The next prime is 55770413. The reversal of 55770391 is 19307755.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55770391 - 2¹ = 55770389 is a prime.

It is a super-2 number, since 2×55770391² = 6220673024585762, which contains 22 as substring.

Together with 55770389, 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 55770391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55770311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27885195 + 27885196.

It is an arithmetic number, because the mean of its divisors is an integer number (27885196).

Almost surely, 2^55770391 is an apocalyptic number.

55770391 is a deficient number, since it is larger than the sum of its proper divisors (1).

55770391 is an equidigital number, since it uses as much as digits as its factorization.

55770391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 33075, while the sum is 37.

The square root of 55770391 is about 7467.9576190549. The cubic root of 55770391 is about 382.0626319277.

The spelling of 55770391 in words is "fifty-five million, seven hundred seventy thousand, three hundred ninety-one".