21012134100 has 72 divisors (see below), whose sum is σ = 60838606080. Its totient is φ = 5599226880.

The previous prime is 21012134071. The next prime is 21012134119. The reversal of 21012134100 is 143121012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21012134100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 407364 + ... + 456036.

It is an arithmetic number, because the mean of its divisors is an integer number (844980640).

Almost surely, 2^21012134100 is an apocalyptic number.

21012134100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012134100 is an abundant number, since it is smaller than the sum of its proper divisors (39826471980).

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

21012134100 is a wasteful number, since it uses less digits than its factorization.

21012134100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50129 (or 50122 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21012134100 its reverse (143121012), we get a palindrome (21155255112).

The spelling of 21012134100 in words is "twenty-one billion, twelve million, one hundred thirty-four thousand, one hundred".