21100442402 has 16 divisors (see below), whose sum is σ = 34194242040. Its totient is φ = 9707548032.

The previous prime is 21100442333. The next prime is 21100442431. The reversal of 21100442402 is 20424400112.

It can be written as a sum of positive squares in 4 ways, for example, as 15055535401 + 6044907001 = 122701^2 + 77749^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1288277 + ... + 1304552.

Almost surely, 2^21100442402 is an apocalyptic number.

21100442402 is a deficient number, since it is larger than the sum of its proper divisors (13093799638).

21100442402 is a wasteful number, since it uses less digits than its factorization.

21100442402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2593157.

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21100442402 its reverse (20424400112), we get a palindrome (41524842514).

The spelling of 21100442402 in words is "twenty-one billion, one hundred million, four hundred forty-two thousand, four hundred two".