51291895 has 4 divisors (see below), whose sum is σ = 61550280. Its totient is φ = 41033512.

The previous prime is 51291883. The next prime is 51291967. The reversal of 51291895 is 59819215.

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-51291895 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5129185 + ... + 5129194.

It is an arithmetic number, because the mean of its divisors is an integer number (15387570).

Almost surely, 2^51291895 is an apocalyptic number.

51291895 is a deficient number, since it is larger than the sum of its proper divisors (10258385).

51291895 is a wasteful number, since it uses less digits than its factorization.

51291895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10258384.

The product of its digits is 32400, while the sum is 40.

The square root of 51291895 is about 7161.8360076170. The cubic root of 51291895 is about 371.5491295393.

The spelling of 51291895 in words is "fifty-one million, two hundred ninety-one thousand, eight hundred ninety-five".