821220121022102 has 4 divisors (see below), whose sum is σ = 1231830181533156. Its totient is φ = 410610060511050.

The previous prime is 821220121022039. The next prime is 821220121022123. The reversal of 821220121022102 is 201220121022128.

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, 205305030255524 + ... + 205305030255527.

It is an arithmetic number, because the mean of its divisors is an integer number (307957545383289).

Almost surely, 2^{821220121022102} is an apocalyptic number.

821220121022102 is a deficient number, since it is larger than the sum of its proper divisors (410610060511054).

821220121022102 is a wasteful number, since it uses less digits than its factorization.

821220121022102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410610060511053.

The product of its (nonzero) digits is 1024, while the sum is 26.

Adding to 821220121022102 its sum of digits (26), we get a palindrome (821220121022128).

The spelling of 821220121022102 in words is "eight hundred twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, twenty-two thousand, one hundred two".