21012001022100 has 144 divisors (see below), whose sum is σ = 66908433211200. Its totient is φ = 5048740300800.

The previous prime is 21012001022093. The next prime is 21012001022101. The reversal of 21012001022100 is 122010021012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012001022101) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27800875 + ... + 28546674.

It is an arithmetic number, because the mean of its divisors is an integer number (464641897300).

Almost surely, 2^{21012001022100} is an apocalyptic number.

21012001022100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012001022100 is an abundant number, since it is smaller than the sum of its proper divisors (45896432189100).

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

21012001022100 is a wasteful number, since it uses less digits than its factorization.

21012001022100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56347690 (or 56347683 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21012001022100 its reverse (122010021012), we get a palindrome (21134011043112).

The spelling of 21012001022100 in words is "twenty-one trillion, twelve billion, one million, twenty-two thousand, one hundred".