21101111001002 has 4 divisors (see below), whose sum is σ = 31651666501506. Its totient is φ = 10550555500500.

The previous prime is 21101111000941. The next prime is 21101111001011. The reversal of 21101111001002 is 20010011110112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 19639069696801 + 1462041304201 = 4431599^2 + 1209149^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5275277750249 + ... + 5275277750252.

Almost surely, 2^{21101111001002} is an apocalyptic number.

21101111001002 is a deficient number, since it is larger than the sum of its proper divisors (10550555500504).

21101111001002 is a wasteful number, since it uses less digits than its factorization.

21101111001002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10550555500503.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21101111001002 its reverse (20010011110112), we get a palindrome (41111122111114).

It can be divided in two parts, 2110111 and 1001002, that added together give a palindrome (3111113).

The spelling of 21101111001002 in words is "twenty-one trillion, one hundred one billion, one hundred eleven million, one thousand, two".