20391223776 has 384 divisors, whose sum is σ = 71705088000. Its totient is φ = 5015969280.

The previous prime is 20391223753. The next prime is 20391223847. The reversal of 20391223776 is 67732219302.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 6880471 + ... + 6883433.

It is an arithmetic number, because the mean of its divisors is an integer number (186732000).

Almost surely, 2^20391223776 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 20391223776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35852544000).

20391223776 is an abundant number, since it is smaller than the sum of its proper divisors (51313864224).

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

20391223776 is a wasteful number, since it uses less digits than its factorization.

20391223776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3027 (or 3005 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 42.

The spelling of 20391223776 in words is "twenty billion, three hundred ninety-one million, two hundred twenty-three thousand, seven hundred seventy-six".