21002001102 has 24 divisors (see below), whose sum is σ = 45618971736. Its totient is φ = 6983030736.

The previous prime is 21002001091. The next prime is 21002001107. The reversal of 21002001102 is 20110020012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002001107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1462348 + ... + 1476639.

It is an arithmetic number, because the mean of its divisors is an integer number (1900790489).

Almost surely, 2^21002001102 is an apocalyptic number.

21002001102 is an abundant number, since it is smaller than the sum of its proper divisors (24616970634).

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

21002001102 is a wasteful number, since it uses less digits than its factorization.

21002001102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2939392 (or 2939389 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21002001102 its reverse (20110020012), we get a palindrome (41112021114).

The spelling of 21002001102 in words is "twenty-one billion, two million, one thousand, one hundred two".