21453531331 has 2 divisors, whose sum is σ = 21453531332. Its totient is φ = 21453531330.

The previous prime is 21453531317. The next prime is 21453531353. The reversal of 21453531331 is 13313535412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21453531331 - 2⁵ = 21453531299 is a prime.

It is a super-2 number, since 2×21453531331² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21453531293 and 21453531302.

It is not a weakly prime, because it can be changed into another prime (21453531131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726765665 + 10726765666.

It is an arithmetic number, because the mean of its divisors is an integer number (10726765666).

Almost surely, 2^21453531331 is an apocalyptic number.

21453531331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21453531331 is an equidigital number, since it uses as much as digits as its factorization.

21453531331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16200, while the sum is 31.

The spelling of 21453531331 in words is "twenty-one billion, four hundred fifty-three million, five hundred thirty-one thousand, three hundred thirty-one".