20321715408 has 80 divisors (see below), whose sum is σ = 55643849280. Its totient is φ = 6368790528.

The previous prime is 20321715397. The next prime is 20321715431. The reversal of 20321715408 is 80451712302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 801063 + ... + 826041.

It is an arithmetic number, because the mean of its divisors is an integer number (695548116).

Almost surely, 2^20321715408 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 20321715408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27821924640).

20321715408 is an abundant number, since it is smaller than the sum of its proper divisors (35322133872).

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

20321715408 is a wasteful number, since it uses less digits than its factorization.

20321715408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26004 (or 25998 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The spelling of 20321715408 in words is "twenty billion, three hundred twenty-one million, seven hundred fifteen thousand, four hundred eight".