221323232421 has 12 divisors (see below), whose sum is σ = 321806261920. Its totient is φ = 146571676200.

The previous prime is 221323232399. The next prime is 221323232423. The reversal of 221323232421 is 124232323122.

221323232421 is a `hidden beast` number, since 2 + 2 + 1 + 3 + 2 + 3 + 232 + 421 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-221323232421 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 (221323232423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 81427351 + ... + 81430068.

Almost surely, 2^221323232421 is an apocalyptic number.

It is an amenable number.

221323232421 is a deficient number, since it is larger than the sum of its proper divisors (100483029499).

221323232421 is a wasteful number, since it uses less digits than its factorization.

221323232421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162857576 (or 162857573 counting only the distinct ones).

The product of its digits is 6912, while the sum is 27.

Adding to 221323232421 its reverse (124232323122), we get a palindrome (345555555543).

The spelling of 221323232421 in words is "two hundred twenty-one billion, three hundred twenty-three million, two hundred thirty-two thousand, four hundred twenty-one".