421402413221 has 4 divisors (see below), whose sum is σ = 425574714444. Its totient is φ = 417230112000.

The previous prime is 421402413217. The next prime is 421402413251. The reversal of 421402413221 is 122314204124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 392464660900 + 28937752321 = 626470^2 + 170111^2 .

It is a cyclic number.

It is not a de Polignac number, because 421402413221 - 2² = 421402413217 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 (421402413251) 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, 2086150460 + ... + 2086150661.

It is an arithmetic number, because the mean of its divisors is an integer number (106393678611).

Almost surely, 2^421402413221 is an apocalyptic number.

It is an amenable number.

421402413221 is a deficient number, since it is larger than the sum of its proper divisors (4172301223).

421402413221 is a wasteful number, since it uses less digits than its factorization.

421402413221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4172301222.

The product of its (nonzero) digits is 3072, while the sum is 26.

Adding to 421402413221 its reverse (122314204124), we get a palindrome (543716617345).

The spelling of 421402413221 in words is "four hundred twenty-one billion, four hundred two million, four hundred thirteen thousand, two hundred twenty-one".