1955555591 has 16 divisors (see below), whose sum is σ = 2185941120. Its totient is φ = 1734052320.

The previous prime is 1955555587. The next prime is 1955555621.

1955555591 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1955555591 - 2² = 1955555587 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1955555501) 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, 403901 + ... + 408713.

It is an arithmetic number, because the mean of its divisors is an integer number (136621320).

Almost surely, 2^1955555591 is an apocalyptic number.

1955555591 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1955555591 is a deficient number, since it is larger than the sum of its proper divisors (230385529).

1955555591 is a wasteful number, since it uses less digits than its factorization.

1955555591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5726.

The product of its digits is 1265625, while the sum is 50.

The square root of 1955555591 is about 44221.6642721642. The cubic root of 1955555591 is about 1250.5183111332.

The spelling of 1955555591 in words is "one billion, nine hundred fifty-five million, five hundred fifty-five thousand, five hundred ninety-one".