21001100122210 has 16 divisors (see below), whose sum is σ = 40709824852536. Its totient is φ = 7754252352768.

The previous prime is 21001100122199. The next prime is 21001100122231. The reversal of 21001100122210 is 1222100110012.

It can be written as a sum of positive squares in 4 ways, for example, as 16252435907761 + 4748664214449 = 4031431^2 + 2179143^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

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, 80773461879 + ... + 80773462138.

Almost surely, 2^{21001100122210} is an apocalyptic number.

21001100122210 is a deficient number, since it is larger than the sum of its proper divisors (19708724730326).

21001100122210 is a wasteful number, since it uses less digits than its factorization.

21001100122210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161546924037.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21001100122210 its reverse (1222100110012), we get a palindrome (22223200232222).

The spelling of 21001100122210 in words is "twenty-one trillion, one billion, one hundred million, one hundred twenty-two thousand, two hundred ten".