21020021120 has 64 divisors (see below), whose sum is σ = 57429712800. Its totient is φ = 7206862848.

The previous prime is 21020021101. The next prime is 21020021131. The reversal of 21020021120 is 2112002012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

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, 2341505 + ... + 2350464.

Almost surely, 2^21020021120 is an apocalyptic number.

21020021120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020021120 is an abundant number, since it is smaller than the sum of its proper divisors (36409691680).

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

21020021120 is an equidigital number, since it uses as much as digits as its factorization.

21020021120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4691995 (or 4691983 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21020021120 its reverse (2112002012), we get a palindrome (23132023132).

The spelling of 21020021120 in words is "twenty-one billion, twenty million, twenty-one thousand, one hundred twenty".