21002002902 has 24 divisors (see below), whose sum is σ = 46080347040. Its totient is φ = 6912051120.

The previous prime is 21002002877. The next prime is 21002002919. The reversal of 21002002902 is 20920020012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7383249 + ... + 7386092.

It is an arithmetic number, because the mean of its divisors is an integer number (1920014460).

Almost surely, 2^21002002902 is an apocalyptic number.

21002002902 is an abundant number, since it is smaller than the sum of its proper divisors (25078344138).

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

21002002902 is a wasteful number, since it uses less digits than its factorization.

21002002902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14769428 (or 14769425 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21002002902 its reverse (20920020012), we get a palindrome (41922022914).

It can be divided in two parts, 2100 and 2002902, that added together give a palindrome (2005002).

The spelling of 21002002902 in words is "twenty-one billion, two million, two thousand, nine hundred two".