21052513020 has 192 divisors, whose sum is σ = 73616449536. Its totient is φ = 4367166720.

The previous prime is 21052513003. The next prime is 21052513039. The reversal of 21052513020 is 2031525012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2985619 + ... + 2992661.

It is an arithmetic number, because the mean of its divisors is an integer number (383419008).

Almost surely, 2^21052513020 is an apocalyptic number.

21052513020 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 21052513020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36808224768).

21052513020 is an abundant number, since it is smaller than the sum of its proper divisors (52563936516).

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

21052513020 is a wasteful number, since it uses less digits than its factorization.

21052513020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7720 (or 7718 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The spelling of 21052513020 in words is "twenty-one billion, fifty-two million, five hundred thirteen thousand, twenty".