420013523221 has 4 divisors (see below), whose sum is σ = 427938306732. Its totient is φ = 412088739712.

The previous prime is 420013523219. The next prime is 420013523257. The reversal of 420013523221 is 122325310024.

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 236560640625 + 183452882596 = 486375^2 + 428314^2 .

It is a cyclic number.

It is not a de Polignac number, because 420013523221 - 2¹ = 420013523219 is a prime.

It is a super-2 number, since 2×420013523221² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420013523821) 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, 3962391676 + ... + 3962391781.

It is an arithmetic number, because the mean of its divisors is an integer number (106984576683).

Almost surely, 2^420013523221 is an apocalyptic number.

It is an amenable number.

420013523221 is a deficient number, since it is larger than the sum of its proper divisors (7924783511).

420013523221 is an equidigital number, since it uses as much as digits as its factorization.

420013523221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7924783510.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 420013523221 its reverse (122325310024), we get a palindrome (542338833245).

The spelling of 420013523221 in words is "four hundred twenty billion, thirteen million, five hundred twenty-three thousand, two hundred twenty-one".