21000021010100 has 72 divisors (see below), whose sum is σ = 50204982987936. Its totient is φ = 7560763600000.

The previous prime is 21000021010097. The next prime is 21000021010103. The reversal of 21000021010100 is 101012000012.

It is an interprime number because it is at equal distance from previous prime (21000021010097) and next prime (21000021010103).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000021010103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 94398446 + ... + 94620645.

It is an arithmetic number, because the mean of its divisors is an integer number (697291430388).

Almost surely, 2^{21000021010100} is an apocalyptic number.

21000021010100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000021010100 is an abundant number, since it is smaller than the sum of its proper divisors (29204961977836).

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

21000021010100 is a wasteful number, since it uses less digits than its factorization.

21000021010100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189019217 (or 189019210 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21000021010100 its reverse (101012000012), we get a palindrome (21101033010112).

The spelling of 21000021010100 in words is "twenty-one trillion, twenty-one million, ten thousand, one hundred".