20809976454 has 96 divisors (see below), whose sum is σ = 48144844800. Its totient is φ = 6473592576.

The previous prime is 20809976431. The next prime is 20809976477. The reversal of 20809976454 is 45467990802.

20809976454 is a `hidden beast` number, since 20 + 80 + 9 + 97 + 6 + 454 = 666.

It is an interprime number because it is at equal distance from previous prime (20809976431) and next prime (20809976477).

It is a self number, because there is not a number n which added to its sum of digits gives 20809976454.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 34283019 + ... + 34283625.

It is an arithmetic number, because the mean of its divisors is an integer number (501508800).

Almost surely, 2^20809976454 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20809976454, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24072422400).

20809976454 is an abundant number, since it is smaller than the sum of its proper divisors (27334868346).

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

20809976454 is a wasteful number, since it uses less digits than its factorization.

20809976454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1394 (or 1391 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 20809976454 in words is "twenty billion, eight hundred nine million, nine hundred seventy-six thousand, four hundred fifty-four".