21021223123020 has 96 divisors (see below), whose sum is σ = 61434225957888. Its totient is φ = 5360564906752.

The previous prime is 21021223122827. The next prime is 21021223123037. The reversal of 21021223123020 is 2032132212012.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3461017 + ... + 7349903.

It is an arithmetic number, because the mean of its divisors is an integer number (639939853728).

Almost surely, 2^{21021223123020} is an apocalyptic number.

21021223123020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21021223123020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30717112978944).

21021223123020 is an abundant number, since it is smaller than the sum of its proper divisors (40413002834868).

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

21021223123020 is a wasteful number, since it uses less digits than its factorization.

21021223123020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3892839 (or 3892837 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21021223123020 its reverse (2032132212012), we get a palindrome (23053355335032).

The spelling of 21021223123020 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-three million, one hundred twenty-three thousand, twenty".