21012101200 has 60 divisors (see below), whose sum is σ = 51002095900. Its totient is φ = 8318177280.

The previous prime is 21012101093. The next prime is 21012101251. The reversal of 21012101200 is 210121012.

It can be written as a sum of positive squares in 6 ways, for example, as 203461696 + 20808639504 = 14264^2 + 144252^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 231975 + ... + 309574.

Almost surely, 2^21012101200 is an apocalyptic number.

21012101200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012101200 is an abundant number, since it is smaller than the sum of its proper divisors (29989994700).

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

21012101200 is a wasteful number, since it uses less digits than its factorization.

21012101200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541664 (or 541653 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21012101200 its reverse (210121012), we get a palindrome (21222222212).

21012101200 divided by its reverse (210121012) gives a square (100 = 10²).

The spelling of 21012101200 in words is "twenty-one billion, twelve million, one hundred one thousand, two hundred".