55780191 has 16 divisors (see below), whose sum is σ = 85304320. Its totient is φ = 35986680.

The previous prime is 55780189. The next prime is 55780223. The reversal of 55780191 is 19108755.

It is not a de Polignac number, because 55780191 - 2¹ = 55780189 is a prime.

It is a super-2 number, since 2×55780191² = 6222859415992962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55780121) 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, 32485 + ... + 34158.

It is an arithmetic number, because the mean of its divisors is an integer number (5331520).

Almost surely, 2^55780191 is an apocalyptic number.

55780191 is a deficient number, since it is larger than the sum of its proper divisors (29524129).

55780191 is a wasteful number, since it uses less digits than its factorization.

55780191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66683 (or 66677 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 36.

The square root of 55780191 is about 7468.6137267903. The cubic root of 55780191 is about 382.0850093604.

The spelling of 55780191 in words is "fifty-five million, seven hundred eighty thousand, one hundred ninety-one".