51205520253 has 4 divisors (see below), whose sum is σ = 68274027008. Its totient is φ = 34137013500.

The previous prime is 51205520209. The next prime is 51205520269. The reversal of 51205520253 is 35202550215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51205520253 - 2¹⁸ = 51205258109 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51205520253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51205525253) 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, 8534253373 + ... + 8534253378.

It is an arithmetic number, because the mean of its divisors is an integer number (17068506752).

Almost surely, 2^51205520253 is an apocalyptic number.

It is an amenable number.

51205520253 is a deficient number, since it is larger than the sum of its proper divisors (17068506755).

51205520253 is a wasteful number, since it uses less digits than its factorization.

51205520253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17068506754.

The product of its (nonzero) digits is 15000, while the sum is 30.

The spelling of 51205520253 in words is "fifty-one billion, two hundred five million, five hundred twenty thousand, two hundred fifty-three".