21001021210102 has 4 divisors (see below), whose sum is σ = 31501531815156. Its totient is φ = 10500510605050.

The previous prime is 21001021210097. The next prime is 21001021210129. The reversal of 21001021210102 is 20101212010012.

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

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, 5250255302524 + ... + 5250255302527.

It is an arithmetic number, because the mean of its divisors is an integer number (7875382953789).

Almost surely, 2^{21001021210102} is an apocalyptic number.

21001021210102 is a deficient number, since it is larger than the sum of its proper divisors (10500510605054).

21001021210102 is a wasteful number, since it uses less digits than its factorization.

21001021210102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500510605053.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21001021210102 its reverse (20101212010012), we get a palindrome (41102233220114).

The spelling of 21001021210102 in words is "twenty-one trillion, one billion, twenty-one million, two hundred ten thousand, one hundred two".