20491954484400 has 1440 divisors, whose sum is σ = 88940437447680. Its totient is φ = 4429587824640.

The previous prime is 20491954484369. The next prime is 20491954484413. The reversal of 20491954484400 is 448445919402.

20491954484400 is a `hidden beast` number, since 2 + 0 + 4 + 9 + 19 + 544 + 84 + 4 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 1392771444 + ... + 1392786156.

It is an arithmetic number, because the mean of its divisors is an integer number (61764192672).

Almost surely, 2^{20491954484400} is an apocalyptic number.

20491954484400 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 20491954484400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44470218723840).

20491954484400 is an abundant number, since it is smaller than the sum of its proper divisors (68448482963280).

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

20491954484400 is a wasteful number, since it uses less digits than its factorization.

20491954484400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14865 (or 14842 counting only the distinct ones).

The product of its (nonzero) digits is 6635520, while the sum is 54.

The spelling of 20491954484400 in words is "twenty trillion, four hundred ninety-one billion, nine hundred fifty-four million, four hundred eighty-four thousand, four hundred".