20315316242521 has 4 divisors (see below), whose sum is σ = 21384543413200. Its totient is φ = 19246089071844.

The previous prime is 20315316242479. The next prime is 20315316242539. The reversal of 20315316242521 is 12524261351302.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 20315316242521 - 2¹⁹ = 20315315718233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20315316242561) 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, 534613585311 + ... + 534613585348.

It is an arithmetic number, because the mean of its divisors is an integer number (5346135853300).

Almost surely, 2^{20315316242521} is an apocalyptic number.

It is an amenable number.

20315316242521 is a deficient number, since it is larger than the sum of its proper divisors (1069227170679).

20315316242521 is a wasteful number, since it uses less digits than its factorization.

20315316242521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1069227170678.

The product of its (nonzero) digits is 86400, while the sum is 37.

Adding to 20315316242521 its reverse (12524261351302), we get a palindrome (32839577593823).

The spelling of 20315316242521 in words is "twenty trillion, three hundred fifteen billion, three hundred sixteen million, two hundred forty-two thousand, five hundred twenty-one".