51720995 has 4 divisors (see below), whose sum is σ = 62065200. Its totient is φ = 41376792.

The previous prime is 51720947. The next prime is 51721001. The reversal of 51720995 is 59902715.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 59902715 = 5 ⋅11980543.

It is a cyclic number.

It is not a de Polignac number, because 51720995 - 2¹⁰ = 51719971 is a prime.

It is a super-2 number, since 2×51720995² = 5350122647580050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5172095 + ... + 5172104.

It is an arithmetic number, because the mean of its divisors is an integer number (15516300).

Almost surely, 2^51720995 is an apocalyptic number.

51720995 is a deficient number, since it is larger than the sum of its proper divisors (10344205).

51720995 is a wasteful number, since it uses less digits than its factorization.

51720995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10344204.

The product of its (nonzero) digits is 28350, while the sum is 38.

The square root of 51720995 is about 7191.7310155483. The cubic root of 51720995 is about 372.5823609605.

It can be divided in two parts, 517 and 20995, that added together give a palindrome (21512).

The spelling of 51720995 in words is "fifty-one million, seven hundred twenty thousand, nine hundred ninety-five".