21522043213 has 4 divisors (see below), whose sum is σ = 23478592608. Its totient is φ = 19565493820.

The previous prime is 21522043171. The next prime is 21522043243. The reversal of 21522043213 is 31234022512.

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 21522043213 - 2²⁵ = 21488488781 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 (21522043243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 978274681 + ... + 978274702.

It is an arithmetic number, because the mean of its divisors is an integer number (5869648152).

Almost surely, 2^21522043213 is an apocalyptic number.

It is an amenable number.

21522043213 is a deficient number, since it is larger than the sum of its proper divisors (1956549395).

21522043213 is a wasteful number, since it uses less digits than its factorization.

21522043213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1956549394.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21522043213 its reverse (31234022512), we get a palindrome (52756065725).

The spelling of 21522043213 in words is "twenty-one billion, five hundred twenty-two million, forty-three thousand, two hundred thirteen".