21010020020 has 24 divisors (see below), whose sum is σ = 48132046368. Its totient is φ = 7640007200.

The previous prime is 21010020007. The next prime is 21010020047. The reversal of 21010020020 is 2002001012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47749826 + ... + 47750265.

It is an arithmetic number, because the mean of its divisors is an integer number (2005501932).

Almost surely, 2^21010020020 is an apocalyptic number.

21010020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21010020020 is an abundant number, since it is smaller than the sum of its proper divisors (27122026348).

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

21010020020 is a wasteful number, since it uses less digits than its factorization.

21010020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95500111 (or 95500109 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 21010020020 its reverse (2002001012), we get a palindrome (23012021032).

The spelling of 21010020020 in words is "twenty-one billion, ten million, twenty thousand, twenty".