21011210111020 has 24 divisors (see below), whose sum is σ = 44124391605168. Its totient is φ = 8404322068800.

The previous prime is 21011210110967. The next prime is 21011210111069. The reversal of 21011210111020 is 2011101211012.

It is a happy number.

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 7 ways as a sum of consecutive naturals, for example, 9057046 + ... + 11137885.

It is an arithmetic number, because the mean of its divisors is an integer number (1838516316882).

Almost surely, 2^{21011210111020} is an apocalyptic number.

21011210111020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011210111020 is an abundant number, since it is smaller than the sum of its proper divisors (23113181494148).

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

21011210111020 is a wasteful number, since it uses less digits than its factorization.

21011210111020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20246961 (or 20246959 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21011210111020 its reverse (2011101211012), we get a palindrome (23022311322032).

The spelling of 21011210111020 in words is "twenty-one trillion, eleven billion, two hundred ten million, one hundred eleven thousand, twenty".