51091915 has 16 divisors (see below), whose sum is σ = 70264512. Its totient is φ = 34936704.

The previous prime is 51091913. The next prime is 51091921. The reversal of 51091915 is 51919015.

It is a cyclic number.

It is not a de Polignac number, because 51091915 - 2¹ = 51091913 is a prime.

It is a super-2 number, since 2×51091915² = 5220767556734450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51091913) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12057 + ... + 15733.

It is an arithmetic number, because the mean of its divisors is an integer number (4391532).

Almost surely, 2^51091915 is an apocalyptic number.

51091915 is a deficient number, since it is larger than the sum of its proper divisors (19172597).

51091915 is a wasteful number, since it uses less digits than its factorization.

51091915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4086.

The product of its (nonzero) digits is 2025, while the sum is 31.

The square root of 51091915 is about 7147.8608688194. The cubic root of 51091915 is about 371.0656277466.

The spelling of 51091915 in words is "fifty-one million, ninety-one thousand, nine hundred fifteen".