221421207126257 has 4 divisors (see below), whose sum is σ = 221547086154240. Its totient is φ = 221295328098276.

The previous prime is 221421207126151. The next prime is 221421207126263. The reversal of 221421207126257 is 752621702124122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221421207126257 - 2⁸ = 221421207126001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221421207122257) 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, 62939511353 + ... + 62939514870.

It is an arithmetic number, because the mean of its divisors is an integer number (55386771538560).

Almost surely, 2^{221421207126257} is an apocalyptic number.

It is an amenable number.

221421207126257 is a deficient number, since it is larger than the sum of its proper divisors (125879027983).

221421207126257 is a wasteful number, since it uses less digits than its factorization.

221421207126257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125879027982.

The product of its (nonzero) digits is 376320, while the sum is 44.

The spelling of 221421207126257 in words is "two hundred twenty-one trillion, four hundred twenty-one billion, two hundred seven million, one hundred twenty-six thousand, two hundred fifty-seven".