221535257035421 has 16 divisors (see below), whose sum is σ = 257039708146176. Its totient is φ = 186996659301936.

The previous prime is 221535257035373. The next prime is 221535257035429. The reversal of 221535257035421 is 124530752535122.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221535257035421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221535257035429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69866711 + ... + 72968676.

It is an arithmetic number, because the mean of its divisors is an integer number (16064981759136).

Almost surely, 2^{221535257035421} is an apocalyptic number.

It is an amenable number.

221535257035421 is a deficient number, since it is larger than the sum of its proper divisors (35504451110755).

221535257035421 is a wasteful number, since it uses less digits than its factorization.

221535257035421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142838768.

The product of its (nonzero) digits is 2520000, while the sum is 47.

The spelling of 221535257035421 in words is "two hundred twenty-one trillion, five hundred thirty-five billion, two hundred fifty-seven million, thirty-five thousand, four hundred twenty-one".