21002101012 has 6 divisors (see below), whose sum is σ = 36753676778. Its totient is φ = 10501050504.

The previous prime is 21002100997. The next prime is 21002101033. The reversal of 21002101012 is 21010120012.

It can be written as a sum of positive squares in only one way, i.e., 17467322896 + 3534778116 = 132164^2 + 59454^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21002101012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625262623 + ... + 2625262630.

Almost surely, 2^21002101012 is an apocalyptic number.

It is an amenable number.

21002101012 is a deficient number, since it is larger than the sum of its proper divisors (15751575766).

21002101012 is a wasteful number, since it uses less digits than its factorization.

21002101012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5250525257 (or 5250525255 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21002101012 its reverse (21010120012), we get a palindrome (42012221024).

The spelling of 21002101012 in words is "twenty-one billion, two million, one hundred one thousand, twelve".