55981369 has 4 divisors (see below), whose sum is σ = 56036596. Its totient is φ = 55926144.

The previous prime is 55981363. The next prime is 55981421. The reversal of 55981369 is 96318955.

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 51194025 + 4787344 = 7155^2 + 2188^2 .

It is a cyclic number.

It is not a de Polignac number, because 55981369 - 2³ = 55981361 is a prime.

It is a super-3 number, since 3×55981369³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55981361) 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, 26064 + ... + 28129.

It is an arithmetic number, because the mean of its divisors is an integer number (14009149).

Almost surely, 2^55981369 is an apocalyptic number.

It is an amenable number.

55981369 is a deficient number, since it is larger than the sum of its proper divisors (55227).

55981369 is a wasteful number, since it uses less digits than its factorization.

55981369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55226.

The product of its digits is 291600, while the sum is 46.

The square root of 55981369 is about 7482.0698339430. The cubic root of 55981369 is about 382.5438034902.

The spelling of 55981369 in words is "fifty-five million, nine hundred eighty-one thousand, three hundred sixty-nine".