20523551513 has 8 divisors (see below), whose sum is σ = 20914148808. Its totient is φ = 20133078784.

The previous prime is 20523551501. The next prime is 20523551533. The reversal of 20523551513 is 31515532502.

It can be written as a sum of positive squares in 4 ways, for example, as 10174151689 + 10349399824 = 100867^2 + 101732^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20523551513 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 20523551513.

It is not an unprimeable number, because it can be changed into a prime (20523551533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344081 + ... + 399297.

It is an arithmetic number, because the mean of its divisors is an integer number (2614268601).

Almost surely, 2^20523551513 is an apocalyptic number.

It is an amenable number.

20523551513 is a deficient number, since it is larger than the sum of its proper divisors (390597295).

20523551513 is an equidigital number, since it uses as much as digits as its factorization.

20523551513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62283.

The product of its (nonzero) digits is 22500, while the sum is 32.

The spelling of 20523551513 in words is "twenty billion, five hundred twenty-three million, five hundred fifty-one thousand, five hundred thirteen".