21525421045 has 8 divisors (see below), whose sum is σ = 25831464120. Its totient is φ = 17219697600.

The previous prime is 21525421039. The next prime is 21525421067. The reversal of 21525421045 is 54012452512.

It can be written as a sum of positive squares in 4 ways, for example, as 3057426436 + 18467994609 = 55294^2 + 135897^2 .

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

It is not a de Polignac number, because 21525421045 - 2⁹ = 21525420533 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21525420998 and 21525421016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108751 + ... + 234259.

It is an arithmetic number, because the mean of its divisors is an integer number (3228933015).

Almost surely, 2^21525421045 is an apocalyptic number.

It is an amenable number.

21525421045 is a deficient number, since it is larger than the sum of its proper divisors (4306043075).

21525421045 is a wasteful number, since it uses less digits than its factorization.

21525421045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159815.

The product of its (nonzero) digits is 16000, while the sum is 31.

Adding to 21525421045 its reverse (54012452512), we get a palindrome (75537873557).

The spelling of 21525421045 in words is "twenty-one billion, five hundred twenty-five million, four hundred twenty-one thousand, forty-five".