21224353631451 has 4 divisors (see below), whose sum is σ = 28299138175272. Its totient is φ = 14149569087632.

The previous prime is 21224353631449. The next prime is 21224353631483. The reversal of 21224353631451 is 15413635342212.

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

It is a cyclic number.

It is not a de Polignac number, because 21224353631451 - 2¹ = 21224353631449 is a prime.

It is a super-2 number, since 2×21224353631451² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21224353631431) 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, 3537392271906 + ... + 3537392271911.

It is an arithmetic number, because the mean of its divisors is an integer number (7074784543818).

Almost surely, 2^{21224353631451} is an apocalyptic number.

21224353631451 is a deficient number, since it is larger than the sum of its proper divisors (7074784543821).

21224353631451 is an equidigital number, since it uses as much as digits as its factorization.

21224353631451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7074784543820.

The product of its digits is 518400, while the sum is 42.

Adding to 21224353631451 its reverse (15413635342212), we get a palindrome (36637988973663).

The spelling of 21224353631451 in words is "twenty-one trillion, two hundred twenty-four billion, three hundred fifty-three million, six hundred thirty-one thousand, four hundred fifty-one".