21625018253 has 4 divisors (see below), whose sum is σ = 21625313628. Its totient is φ = 21624722880.

The previous prime is 21625018241. The next prime is 21625018297. The reversal of 21625018253 is 35281052612.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7035518884 + 14589499369 = 83878^2 + 120787^2 .

It is a cyclic number.

It is not a de Polignac number, because 21625018253 - 2¹² = 21625014157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21625018213) 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, 53363 + ... + 214703.

It is an arithmetic number, because the mean of its divisors is an integer number (5406328407).

Almost surely, 2^21625018253 is an apocalyptic number.

It is an amenable number.

21625018253 is a deficient number, since it is larger than the sum of its proper divisors (295375).

21625018253 is a wasteful number, since it uses less digits than its factorization.

21625018253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295374.

The product of its (nonzero) digits is 28800, while the sum is 35.

The spelling of 21625018253 in words is "twenty-one billion, six hundred twenty-five million, eighteen thousand, two hundred fifty-three".