21323510040 has 256 divisors, whose sum is σ = 77893125120. Its totient is φ = 4558602240.

The previous prime is 21323510029. The next prime is 21323510081. The reversal of 21323510040 is 4001532312.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21323509989 and 21323510016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2323060 + ... + 2332220.

It is an arithmetic number, because the mean of its divisors is an integer number (304270020).

Almost surely, 2^21323510040 is an apocalyptic number.

21323510040 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 21323510040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38946562560).

21323510040 is an abundant number, since it is smaller than the sum of its proper divisors (56569615080).

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

21323510040 is a wasteful number, since it uses less digits than its factorization.

21323510040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9362 (or 9358 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The spelling of 21323510040 in words is "twenty-one billion, three hundred twenty-three million, five hundred ten thousand, forty".