51115091 has 4 divisors (see below), whose sum is σ = 51278712. Its totient is φ = 50951472.

The previous prime is 51115079. The next prime is 51115109. The reversal of 51115091 is 19051115.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51115091 is a prime.

It is a super-2 number, since 2×51115091² = 5225505055876562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51112091) 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, 81341 + ... + 81966.

It is an arithmetic number, because the mean of its divisors is an integer number (12819678).

Almost surely, 2^51115091 is an apocalyptic number.

51115091 is a deficient number, since it is larger than the sum of its proper divisors (163621).

51115091 is a wasteful number, since it uses less digits than its factorization.

51115091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163620.

The product of its (nonzero) digits is 225, while the sum is 23.

The square root of 51115091 is about 7149.4818693385. The cubic root of 51115091 is about 371.1217261005.

The spelling of 51115091 in words is "fifty-one million, one hundred fifteen thousand, ninety-one".