21213412124020 has 12 divisors (see below), whose sum is σ = 44548165460484. Its totient is φ = 8485364849600.

The previous prime is 21213412123963. The next prime is 21213412124027. The reversal of 21213412124020 is 2042121431212.

It can be written as a sum of positive squares in 2 ways, for example, as 2388174618384 + 18825237505636 = 1545372^2 + 4338806^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213412124027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530335303081 + ... + 530335303120.

It is an arithmetic number, because the mean of its divisors is an integer number (3712347121707).

Almost surely, 2^{21213412124020} is an apocalyptic number.

21213412124020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213412124020 is an abundant number, since it is smaller than the sum of its proper divisors (23334753336464).

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

21213412124020 is a wasteful number, since it uses less digits than its factorization.

21213412124020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060670606210 (or 1060670606208 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

Adding to 21213412124020 its reverse (2042121431212), we get a palindrome (23255533555232).

The spelling of 21213412124020 in words is "twenty-one trillion, two hundred thirteen billion, four hundred twelve million, one hundred twenty-four thousand, twenty".