21221351801426 has 12 divisors (see below), whose sum is σ = 37029093449598. Its totient is φ = 9094865057712.

The previous prime is 21221351801411. The next prime is 21221351801449. The reversal of 21221351801426 is 62410815312212.

It can be written as a sum of positive squares in only one way, i.e., 12505778395201 + 8715573406225 = 3536351^2 + 2952215^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21221351801426.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 108272202971 + ... + 108272203166.

Almost surely, 2^{21221351801426} is an apocalyptic number.

21221351801426 is a deficient number, since it is larger than the sum of its proper divisors (15807741648172).

21221351801426 is a wasteful number, since it uses less digits than its factorization.

21221351801426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216544406153 (or 216544406146 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 38.

The spelling of 21221351801426 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred fifty-one million, eight hundred one thousand, four hundred twenty-six".