21221240120404 has 12 divisors (see below), whose sum is σ = 37137225536404. Its totient is φ = 10610604252864.

The previous prime is 21221240120371. The next prime is 21221240120407. The reversal of 21221240120404 is 40402104212212.

It can be written as a sum of positive squares in 2 ways, for example, as 19075073720004 + 2146166400400 = 4367502^2 + 1464980^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221240120407) 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, 618897 + ... + 6544120.

Almost surely, 2^{21221240120404} is an apocalyptic number.

It is an amenable number.

21221240120404 is a deficient number, since it is larger than the sum of its proper divisors (15915985416000).

21221240120404 is a wasteful number, since it uses less digits than its factorization.

21221240120404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7903674 (or 7903672 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 25.

Adding to 21221240120404 its reverse (40402104212212), we get a palindrome (61623344332616).

The spelling of 21221240120404 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred forty million, one hundred twenty thousand, four hundred four".