221421251705421 has 32 divisors (see below), whose sum is σ = 325552163328000. Its totient is φ = 133313610725568.

The previous prime is 221421251705371. The next prime is 221421251705509. The reversal of 221421251705421 is 124507152124122.

221421251705421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221421251705421 - 2⁷ = 221421251705293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221421251705421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221421251709421) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 847661505 + ... + 847922678.

It is an arithmetic number, because the mean of its divisors is an integer number (10173505104000).

Almost surely, 2^{221421251705421} is an apocalyptic number.

It is an amenable number.

221421251705421 is a deficient number, since it is larger than the sum of its proper divisors (104130911622579).

221421251705421 is a wasteful number, since it uses less digits than its factorization.

221421251705421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1695584313.

The product of its (nonzero) digits is 89600, while the sum is 39.

The spelling of 221421251705421 in words is "two hundred twenty-one trillion, four hundred twenty-one billion, two hundred fifty-one million, seven hundred five thousand, four hundred twenty-one".