21500522150413 has 4 divisors (see below), whose sum is σ = 21525038140060. Its totient is φ = 21476006160768.

The previous prime is 21500522150351. The next prime is 21500522150441. The reversal of 21500522150413 is 31405122500512.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10651522286889 + 10848999863524 = 3263667^2 + 3293782^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21500522150413 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 (21500522150453) 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, 12257993508 + ... + 12257995261.

It is an arithmetic number, because the mean of its divisors is an integer number (5381259535015).

Almost surely, 2^{21500522150413} is an apocalyptic number.

It is an amenable number.

21500522150413 is a deficient number, since it is larger than the sum of its proper divisors (24515989647).

21500522150413 is an equidigital number, since it uses as much as digits as its factorization.

21500522150413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24515989646.

The product of its (nonzero) digits is 12000, while the sum is 31.

Adding to 21500522150413 its reverse (31405122500512), we get a palindrome (52905644650925).

The spelling of 21500522150413 in words is "twenty-one trillion, five hundred billion, five hundred twenty-two million, one hundred fifty thousand, four hundred thirteen".