21246437522 has 6 divisors (see below), whose sum is σ = 31869965493. Its totient is φ = 10623115692.

The previous prime is 21246437501. The next prime is 21246437551. The reversal of 21246437522 is 22573464212.

It can be written as a sum of positive squares in 2 ways, for example, as 18074382481 + 3172055041 = 134441^2 + 56321^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=103069.

It is a super-2 number, since 2×21246437522² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 154604 + ... + 257672.

Almost surely, 2^21246437522 is an apocalyptic number.

21246437522 is a deficient number, since it is larger than the sum of its proper divisors (10623527971).

21246437522 is an frugal number, since it uses more digits than its factorization.

21246437522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206140 (or 103071 counting only the distinct ones).

The product of its digits is 161280, while the sum is 38.

The spelling of 21246437522 in words is "twenty-one billion, two hundred forty-six million, four hundred thirty-seven thousand, five hundred twenty-two".