451211221521 has 8 divisors (see below), whose sum is σ = 668461068960. Its totient is φ = 300807480996.

The previous prime is 451211221511. The next prime is 451211221547. The reversal of 451211221521 is 125122112154.

451211221521 is a `hidden beast` number, since 4 + 5 + 1 + 2 + 112 + 21 + 521 = 666.

It is not a de Polignac number, because 451211221521 - 2⁶ = 451211221457 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 16711526723 = 451211221521 / (4 + 5 + 1 + 2 + 1 + 1 + 2 + 2 + 1 + 5 + 2 + 1).

It is not an unprimeable number, because it can be changed into a prime (451211221511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8355763335 + ... + 8355763388.

It is an arithmetic number, because the mean of its divisors is an integer number (83557633620).

Almost surely, 2^451211221521 is an apocalyptic number.

It is an amenable number.

451211221521 is a deficient number, since it is larger than the sum of its proper divisors (217249847439).

451211221521 is a wasteful number, since it uses less digits than its factorization.

451211221521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16711526732 (or 16711526726 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

Adding to 451211221521 its reverse (125122112154), we get a palindrome (576333333675).

The spelling of 451211221521 in words is "four hundred fifty-one billion, two hundred eleven million, two hundred twenty-one thousand, five hundred twenty-one".