21255456113 has 2 divisors, whose sum is σ = 21255456114. Its totient is φ = 21255456112.

The previous prime is 21255456107. The next prime is 21255456151. The reversal of 21255456113 is 31165455212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21022680064 + 232776049 = 144992^2 + 15257^2 .

It is a cyclic number.

It is not a de Polignac number, because 21255456113 - 2⁴ = 21255456097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21255456163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627728056 + 10627728057.

It is an arithmetic number, because the mean of its divisors is an integer number (10627728057).

Almost surely, 2^21255456113 is an apocalyptic number.

It is an amenable number.

21255456113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255456113 is an equidigital number, since it uses as much as digits as its factorization.

21255456113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 35.

Subtracting 21255456113 from its reverse (31165455212), we obtain a palindrome (9909999099).

The spelling of 21255456113 in words is "twenty-one billion, two hundred fifty-five million, four hundred fifty-six thousand, one hundred thirteen".