21023212122 has 32 divisors (see below), whose sum is σ = 50965364160. Its totient is φ = 6370670160.

The previous prime is 21023212103. The next prime is 21023212139. The reversal of 21023212122 is 22121232012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21023212095 and 21023212104.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17695713 + ... + 17696900.

It is an arithmetic number, because the mean of its divisors is an integer number (1592667630).

Almost surely, 2^21023212122 is an apocalyptic number.

21023212122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21023212122 is an abundant number, since it is smaller than the sum of its proper divisors (29942152038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21023212122 is a wasteful number, since it uses less digits than its factorization.

21023212122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35392635 (or 35392629 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21023212122 its reverse (22121232012), we get a palindrome (43144444134).

The spelling of 21023212122 in words is "twenty-one billion, twenty-three million, two hundred twelve thousand, one hundred twenty-two".