55139231 has 8 divisors (see below), whose sum is σ = 63081120. Its totient is φ = 47213568.

The previous prime is 55139221. The next prime is 55139243. The reversal of 55139231 is 13293155.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55139231 is a prime.

It is a super-2 number, since 2×55139231² = 6080669590542722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55139194 and 55139203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55139221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4415 + ... + 11391.

It is an arithmetic number, because the mean of its divisors is an integer number (7885140).

Almost surely, 2^55139231 is an apocalyptic number.

55139231 is a deficient number, since it is larger than the sum of its proper divisors (7941889).

55139231 is a wasteful number, since it uses less digits than its factorization.

55139231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8113.

The product of its digits is 4050, while the sum is 29.

The square root of 55139231 is about 7425.5795060049. The cubic root of 55139231 is about 380.6158780191.

The spelling of 55139231 in words is "fifty-five million, one hundred thirty-nine thousand, two hundred thirty-one".