21231022102 has 4 divisors (see below), whose sum is σ = 31846533156. Its totient is φ = 10615511050.

The previous prime is 21231022093. The next prime is 21231022139. The reversal of 21231022102 is 20122013212.

It is a happy number.

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

It is a super-2 number, since 2×21231022102² (a number of 21 digits) contains 22 as substring.

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, 5307755524 + ... + 5307755527.

It is an arithmetic number, because the mean of its divisors is an integer number (7961633289).

Almost surely, 2^21231022102 is an apocalyptic number.

21231022102 is a deficient number, since it is larger than the sum of its proper divisors (10615511054).

21231022102 is a wasteful number, since it uses less digits than its factorization.

21231022102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10615511053.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21231022102 its reverse (20122013212), we get a palindrome (41353035314).

The spelling of 21231022102 in words is "twenty-one billion, two hundred thirty-one million, twenty-two thousand, one hundred two".