21021021212102 has 4 divisors (see below), whose sum is σ = 31531531818156. Its totient is φ = 10510510606050.

The previous prime is 21021021212053. The next prime is 21021021212131. The reversal of 21021021212102 is 20121212012012.

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, 5255255303024 + ... + 5255255303027.

It is an arithmetic number, because the mean of its divisors is an integer number (7882882954539).

Almost surely, 2^{21021021212102} is an apocalyptic number.

21021021212102 is a deficient number, since it is larger than the sum of its proper divisors (10510510606054).

21021021212102 is a wasteful number, since it uses less digits than its factorization.

21021021212102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10510510606053.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21021021212102 its reverse (20121212012012), we get a palindrome (41142233224114).

The spelling of 21021021212102 in words is "twenty-one trillion, twenty-one billion, twenty-one million, two hundred twelve thousand, one hundred two".