55131511 has 4 divisors (see below), whose sum is σ = 56476224. Its totient is φ = 53786800.

The previous prime is 55131509. The next prime is 55131541. The reversal of 55131511 is 11513155.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11513155 = 5 ⋅2302631.

It is a cyclic number.

It is not a de Polignac number, because 55131511 - 2¹ = 55131509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55131541) 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, 672295 + ... + 672376.

It is an arithmetic number, because the mean of its divisors is an integer number (14119056).

Almost surely, 2^55131511 is an apocalyptic number.

55131511 is a deficient number, since it is larger than the sum of its proper divisors (1344713).

55131511 is a wasteful number, since it uses less digits than its factorization.

55131511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344712.

The product of its digits is 375, while the sum is 22.

The square root of 55131511 is about 7425.0596630600. The cubic root of 55131511 is about 380.5981139476.

Adding to 55131511 its reverse (11513155), we get a palindrome (66644666).

The spelling of 55131511 in words is "fifty-five million, one hundred thirty-one thousand, five hundred eleven".