21001002002 has 8 divisors (see below), whose sum is σ = 31502628300. Its totient is φ = 10500125904.

The previous prime is 21001001971. The next prime is 21001002019. The reversal of 21001002002 is 20020010012.

It can be written as a sum of positive squares in 2 ways, for example, as 19242960961 + 1758041041 = 138719^2 + 41929^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111377 + ... + 233252.

Almost surely, 2^21001002002 is an apocalyptic number.

21001002002 is a deficient number, since it is larger than the sum of its proper divisors (10501626298).

21001002002 is a wasteful number, since it uses less digits than its factorization.

21001002002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375100.

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

Adding to 21001002002 its reverse (20020010012), we get a palindrome (41021012014).

The spelling of 21001002002 in words is "twenty-one billion, one million, two thousand, two".