21120402020 has 48 divisors (see below), whose sum is σ = 45408686400. Its totient is φ = 8247259776.

The previous prime is 21120401999. The next prime is 21120402053. The reversal of 21120402020 is 2020402112.

It is a junction number, because it is equal to n+sod(n) for n = 21120401986 and 21120402004.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1923506 + ... + 1934454.

It is an arithmetic number, because the mean of its divisors is an integer number (946014300).

Almost surely, 2^21120402020 is an apocalyptic number.

21120402020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120402020 is an abundant number, since it is smaller than the sum of its proper divisors (24288284380).

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

21120402020 is a wasteful number, since it uses less digits than its factorization.

21120402020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13244 (or 13242 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21120402020 its reverse (2020402112), we get a palindrome (23140804132).

The spelling of 21120402020 in words is "twenty-one billion, one hundred twenty million, four hundred two thousand, twenty".