21399492608 has 96 divisors (see below), whose sum is σ = 46202017680. Its totient is φ = 9850552320.

The previous prime is 21399492607. The next prime is 21399492641. The reversal of 21399492608 is 80629499312.

It is a self number, because there is not a number n which added to its sum of digits gives 21399492608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21399492607) 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 7 ways as a sum of consecutive naturals, for example, 13071566 + ... + 13073202.

Almost surely, 2^21399492608 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21399492608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23101008840).

21399492608 is an abundant number, since it is smaller than the sum of its proper divisors (24802525072).

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

21399492608 is a wasteful number, since it uses less digits than its factorization.

21399492608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2163 (or 2143 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 53.

The spelling of 21399492608 in words is "twenty-one billion, three hundred ninety-nine million, four hundred ninety-two thousand, six hundred eight".