21522316001 has 4 divisors (see below), whose sum is σ = 21523121412. Its totient is φ = 21521510592.

The previous prime is 21522315977. The next prime is 21522316007. The reversal of 21522316001 is 10061322512.

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 2354190400 + 19168125601 = 48520^2 + 138449^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522316001 - 2²² = 21518121697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21522316007) 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, 361196 + ... + 416541.

It is an arithmetic number, because the mean of its divisors is an integer number (5380780353).

Almost surely, 2^21522316001 is an apocalyptic number.

It is an amenable number.

21522316001 is a deficient number, since it is larger than the sum of its proper divisors (805411).

21522316001 is an equidigital number, since it uses as much as digits as its factorization.

21522316001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805410.

The product of its (nonzero) digits is 720, while the sum is 23.

Adding to 21522316001 its reverse (10061322512), we get a palindrome (31583638513).

The spelling of 21522316001 in words is "twenty-one billion, five hundred twenty-two million, three hundred sixteen thousand, one".