51720523 has 4 divisors (see below), whose sum is σ = 52222768. Its totient is φ = 51218280.

The previous prime is 51720517. The next prime is 51720563. The reversal of 51720523 is 32502715.

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

It is a cyclic number.

It is not a de Polignac number, because 51720523 - 2¹⁷ = 51589451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51720563) 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, 250968 + ... + 251173.

It is an arithmetic number, because the mean of its divisors is an integer number (13055692).

Almost surely, 2^51720523 is an apocalyptic number.

51720523 is a deficient number, since it is larger than the sum of its proper divisors (502245).

51720523 is a wasteful number, since it uses less digits than its factorization.

51720523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502244.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 51720523 is about 7191.6982000081. The cubic root of 51720523 is about 372.5812275754.

The spelling of 51720523 in words is "fifty-one million, seven hundred twenty thousand, five hundred twenty-three".