51191995 has 4 divisors (see below), whose sum is σ = 61430400. Its totient is φ = 40953592.

The previous prime is 51191983. The next prime is 51192007. The reversal of 51191995 is 59919115.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 59919115 = 5 ⋅11983823.

It is an interprime number because it is at equal distance from previous prime (51191983) and next prime (51192007).

It is a cyclic number.

It is not a de Polignac number, because 51191995 - 2⁵ = 51191963 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 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, 5119195 + ... + 5119204.

It is an arithmetic number, because the mean of its divisors is an integer number (15357600).

Almost surely, 2^51191995 is an apocalyptic number.

51191995 is a deficient number, since it is larger than the sum of its proper divisors (10238405).

51191995 is a wasteful number, since it uses less digits than its factorization.

51191995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10238404.

The product of its digits is 18225, while the sum is 40.

The square root of 51191995 is about 7154.8581397537. The cubic root of 51191995 is about 371.3077536394.

The spelling of 51191995 in words is "fifty-one million, one hundred ninety-one thousand, nine hundred ninety-five".