20621239380 has 216 divisors, whose sum is σ = 75273536520. Its totient is φ = 4550837760.

The previous prime is 20621239367. The next prime is 20621239381. The reversal of 20621239380 is 8393212602.

20621239380 is a `hidden beast` number, since 2 + 0 + 621 + 23 + 9 + 3 + 8 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 853776 + 20620385604 = 924^2 + 143598^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20621239381) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 215470 + ... + 296090.

It is an arithmetic number, because the mean of its divisors is an integer number (348488595).

Almost surely, 2^20621239380 is an apocalyptic number.

20621239380 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 20621239380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37636768260).

20621239380 is an abundant number, since it is smaller than the sum of its proper divisors (54652297140).

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

20621239380 is a wasteful number, since it uses less digits than its factorization.

20621239380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80679 (or 80667 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The spelling of 20621239380 in words is "twenty billion, six hundred twenty-one million, two hundred thirty-nine thousand, three hundred eighty".