21790379520 has 960 divisors, whose sum is σ = 97948730880. Its totient is φ = 4347592704.

The previous prime is 21790379509. The next prime is 21790379543. The reversal of 21790379520 is 2597309712.

21790379520 is a `hidden beast` number, since 2 + 1 + 7 + 90 + 37 + 9 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 39835887 + ... + 39836433.

It is an arithmetic number, because the mean of its divisors is an integer number (102029928).

Almost surely, 2^21790379520 is an apocalyptic number.

21790379520 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 21790379520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48974365440).

21790379520 is an abundant number, since it is smaller than the sum of its proper divisors (76158351360).

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

21790379520 is a wasteful number, since it uses less digits than its factorization.

21790379520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615 (or 596 counting only the distinct ones).

The product of its (nonzero) digits is 238140, while the sum is 45.

The spelling of 21790379520 in words is "twenty-one billion, seven hundred ninety million, three hundred seventy-nine thousand, five hundred twenty".