21352234451 has 16 divisors (see below), whose sum is σ = 21792240000. Its totient is φ = 20917561728.

The previous prime is 21352234439. The next prime is 21352234457. The reversal of 21352234451 is 15443225312.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21352234451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21352234457) 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, 6031640 + ... + 6035178.

It is an arithmetic number, because the mean of its divisors is an integer number (1362015000).

Almost surely, 2^21352234451 is an apocalyptic number.

21352234451 is a deficient number, since it is larger than the sum of its proper divisors (440005549).

21352234451 is a wasteful number, since it uses less digits than its factorization.

21352234451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4258.

The product of its digits is 28800, while the sum is 32.

Adding to 21352234451 its reverse (15443225312), we get a palindrome (36795459763).

The spelling of 21352234451 in words is "twenty-one billion, three hundred fifty-two million, two hundred thirty-four thousand, four hundred fifty-one".