21021402100 has 36 divisors (see below), whose sum is σ = 46034965900. Its totient is φ = 8331413760.

The previous prime is 21021402079. The next prime is 21021402107. The reversal of 21021402100 is 120412012.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 2075531364 + 18945870736 = 45558^2 + 137644^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021402107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 953385 + ... + 975184.

Almost surely, 2^21021402100 is an apocalyptic number.

21021402100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021402100 is an abundant number, since it is smaller than the sum of its proper divisors (25013563800).

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

21021402100 is a wasteful number, since it uses less digits than its factorization.

21021402100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1928692 (or 1928685 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21021402100 its reverse (120412012), we get a palindrome (21141814112).

The spelling of 21021402100 in words is "twenty-one billion, twenty-one million, four hundred two thousand, one hundred".