20891325420 has 432 divisors, whose sum is σ = 75944651328. Its totient is φ = 4633251840.

The previous prime is 20891325391. The next prime is 20891325421. The reversal of 20891325420 is 2452319802.

It is a happy number.

20891325420 is a `hidden beast` number, since 2 + 0 + 89 + 1 + 32 + 542 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (20891325421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 45713832 + ... + 45714288.

It is an arithmetic number, because the mean of its divisors is an integer number (175797804).

Almost surely, 2^20891325420 is an apocalyptic number.

20891325420 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 20891325420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37972325664).

20891325420 is an abundant number, since it is smaller than the sum of its proper divisors (55053325908).

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

20891325420 is a wasteful number, since it uses less digits than its factorization.

20891325420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630 (or 618 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 20891325420 in words is "twenty billion, eight hundred ninety-one million, three hundred twenty-five thousand, four hundred twenty".