21020053020 has 192 divisors, whose sum is σ = 63968002560. Its totient is φ = 5139763200.

The previous prime is 21020052973. The next prime is 21020053111. The reversal of 21020053020 is 2035002012.

It is a super-2 number, since 2×21020053020² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

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, 6121224 + ... + 6124656.

It is an arithmetic number, because the mean of its divisors is an integer number (333166680).

Almost surely, 2^21020053020 is an apocalyptic number.

21020053020 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 21020053020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31984001280).

21020053020 is an abundant number, since it is smaller than the sum of its proper divisors (42947949540).

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

21020053020 is a wasteful number, since it uses less digits than its factorization.

21020053020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3636 (or 3634 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

Adding to 21020053020 its reverse (2035002012), we get a palindrome (23055055032).

The spelling of 21020053020 in words is "twenty-one billion, twenty million, fifty-three thousand, twenty".