55981913 has 4 divisors (see below), whose sum is σ = 60288228. Its totient is φ = 51675600.

The previous prime is 55981903. The next prime is 55981927. The reversal of 55981913 is 31918955.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38105929 + 17875984 = 6173^2 + 4228^2 .

It is a cyclic number.

It is not a de Polignac number, because 55981913 - 2⁴ = 55981897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55981903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2153138 + ... + 2153163.

It is an arithmetic number, because the mean of its divisors is an integer number (15072057).

Almost surely, 2^55981913 is an apocalyptic number.

It is an amenable number.

55981913 is a deficient number, since it is larger than the sum of its proper divisors (4306315).

55981913 is a wasteful number, since it uses less digits than its factorization.

55981913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4306314.

The product of its digits is 48600, while the sum is 41.

The square root of 55981913 is about 7482.1061874315. The cubic root of 55981913 is about 382.5450426117.

The spelling of 55981913 in words is "fifty-five million, nine hundred eighty-one thousand, nine hundred thirteen".