21453231331 has 16 divisors (see below), whose sum is σ = 25429970880. Its totient is φ = 17714332800.

The previous prime is 21453231307. The next prime is 21453231409. The reversal of 21453231331 is 13313235412.

It is a cyclic number.

It is not a de Polignac number, because 21453231331 - 2⁵ = 21453231299 is a prime.

It is a super-2 number, since 2×21453231331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21453231331.

It is not an unprimeable number, because it can be changed into a prime (21453531331) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 383896 + ... + 436213.

It is an arithmetic number, because the mean of its divisors is an integer number (1589373180).

Almost surely, 2^21453231331 is an apocalyptic number.

21453231331 is a deficient number, since it is larger than the sum of its proper divisors (3976739549).

21453231331 is a wasteful number, since it uses less digits than its factorization.

21453231331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820254.

The product of its digits is 6480, while the sum is 28.

Adding to 21453231331 its reverse (13313235412), we get a palindrome (34766466743).

The spelling of 21453231331 in words is "twenty-one billion, four hundred fifty-three million, two hundred thirty-one thousand, three hundred thirty-one".