21352234457 has 2 divisors, whose sum is σ = 21352234458. Its totient is φ = 21352234456.

The previous prime is 21352234439. The next prime is 21352234459. The reversal of 21352234457 is 75443225312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15634001296 + 5718233161 = 125036^2 + 75619^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21352234457 is a prime.

Together with 21352234459, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21352234457.

It is not a weakly prime, because it can be changed into another prime (21352234459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676117228 + 10676117229.

It is an arithmetic number, because the mean of its divisors is an integer number (10676117229).

Almost surely, 2^21352234457 is an apocalyptic number.

It is an amenable number.

21352234457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21352234457 is an equidigital number, since it uses as much as digits as its factorization.

21352234457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 201600, while the sum is 38.

Adding to 21352234457 its reverse (75443225312), we get a palindrome (96795459769).

The spelling of 21352234457 in words is "twenty-one billion, three hundred fifty-two million, two hundred thirty-four thousand, four hundred fifty-seven".