21020100010100 has 36 divisors (see below), whose sum is σ = 46726144275468. Its totient is φ = 8202965856000.

The previous prime is 21020100009989. The next prime is 21020100010109. The reversal of 21020100010100 is 101000102012.

It can be written as a sum of positive squares in 6 ways, for example, as 3539974516324 + 17480125493776 = 1881482^2 + 4180924^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020100010109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2563422731 + ... + 2563430930.

Almost surely, 2^{21020100010100} is an apocalyptic number.

21020100010100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020100010100 is an abundant number, since it is smaller than the sum of its proper divisors (25706044265368).

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

21020100010100 is a wasteful number, since it uses less digits than its factorization.

21020100010100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5126853716 (or 5126853709 counting only the distinct ones).

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

Adding to 21020100010100 its reverse (101000102012), we get a palindrome (21121100112112).

The spelling of 21020100010100 in words is "twenty-one trillion, twenty billion, one hundred million, ten thousand, one hundred".