21323393910 has 256 divisors, whose sum is σ = 73669478400. Its totient is φ = 4262118912.

The previous prime is 21323393899. The next prime is 21323393953. The reversal of 21323393910 is 1939332312.

It is a happy number.

21323393910 is a `hidden beast` number, since 213 + 23 + 39 + 391 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 443992 + ... + 489668.

It is an arithmetic number, because the mean of its divisors is an integer number (287771400).

Almost surely, 2^21323393910 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21323393910, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36834739200).

21323393910 is an abundant number, since it is smaller than the sum of its proper divisors (52346084490).

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

21323393910 is a wasteful number, since it uses less digits than its factorization.

21323393910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45732 (or 45726 counting only the distinct ones).

The product of its (nonzero) digits is 26244, while the sum is 36.

The spelling of 21323393910 in words is "twenty-one billion, three hundred twenty-three million, three hundred ninety-three thousand, nine hundred ten".