21335318940 has 96 divisors (see below), whose sum is σ = 64766318400. Its totient is φ = 5216495616.

The previous prime is 21335318887. The next prime is 21335318951. The reversal of 21335318940 is 4981353312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24432 + ... + 208008.

It is an arithmetic number, because the mean of its divisors is an integer number (674649150).

Almost surely, 2^21335318940 is an apocalyptic number.

21335318940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21335318940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32383159200).

21335318940 is an abundant number, since it is smaller than the sum of its proper divisors (43430999460).

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

21335318940 is a wasteful number, since it uses less digits than its factorization.

21335318940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183751 (or 183749 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 39.

The spelling of 21335318940 in words is "twenty-one billion, three hundred thirty-five million, three hundred eighteen thousand, nine hundred forty".