21145431351 has 96 divisors (see below), whose sum is σ = 33600268800. Its totient is φ = 11775836160.

The previous prime is 21145431323. The next prime is 21145431353. The reversal of 21145431351 is 15313454112.

It is not a de Polignac number, because 21145431351 - 2²⁷ = 21011213623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21145431353) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 82277815 + ... + 82278071.

It is an arithmetic number, because the mean of its divisors is an integer number (350002800).

Almost surely, 2^21145431351 is an apocalyptic number.

21145431351 is a deficient number, since it is larger than the sum of its proper divisors (12454837449).

21145431351 is a wasteful number, since it uses less digits than its factorization.

21145431351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565 (or 554 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

Adding to 21145431351 its reverse (15313454112), we get a palindrome (36458885463).

The spelling of 21145431351 in words is "twenty-one billion, one hundred forty-five million, four hundred thirty-one thousand, three hundred fifty-one".