21000101010100 has 18 divisors (see below), whose sum is σ = 45570219192134. Its totient is φ = 8400040404000.

The previous prime is 21000101010041. The next prime is 21000101010107. The reversal of 21000101010100 is 101010100012.

It can be written as a sum of positive squares in 3 ways, for example, as 112769699344 + 20887331310756 = 335812^2 + 4570266^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000101010107) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105000504951 + ... + 105000505150.

Almost surely, 2^{21000101010100} is an apocalyptic number.

21000101010100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000101010100 is an abundant number, since it is smaller than the sum of its proper divisors (24570118182034).

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

21000101010100 is a wasteful number, since it uses less digits than its factorization.

21000101010100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210001010115 (or 210001010108 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21000101010100 its reverse (101010100012), we get a palindrome (21101111110112).

The spelling of 21000101010100 in words is "twenty-one trillion, one hundred one million, ten thousand, one hundred".