21421567264 has 24 divisors (see below), whose sum is σ = 44654518188. Its totient is φ = 10080737280.

The previous prime is 21421567261. The next prime is 21421567267. The reversal of 21421567264 is 46276512412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21421567261) and next prime (21421567267).

It can be written as a sum of positive squares in 2 ways, for example, as 19911467664 + 1510099600 = 141108^2 + 38860^2 .

It is not an unprimeable number, because it can be changed into a prime (21421567261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19688397 + ... + 19689484.

Almost surely, 2^21421567264 is an apocalyptic number.

It is an amenable number.

21421567264 is an abundant number, since it is smaller than the sum of its proper divisors (23232950924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21421567264 is a wasteful number, since it uses less digits than its factorization.

21421567264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39377908 (or 39377900 counting only the distinct ones).

The product of its digits is 161280, while the sum is 40.

The spelling of 21421567264 in words is "twenty-one billion, four hundred twenty-one million, five hundred sixty-seven thousand, two hundred sixty-four".