21459812377 has 2 divisors, whose sum is σ = 21459812378. Its totient is φ = 21459812376.

The previous prime is 21459812323. The next prime is 21459812393. The reversal of 21459812377 is 77321895412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20112628761 + 1347183616 = 141819^2 + 36704^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21459812377 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21459812377.

It is not a weakly prime, because it can be changed into another prime (21459812177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10729906188 + 10729906189.

It is an arithmetic number, because the mean of its divisors is an integer number (10729906189).

Almost surely, 2^21459812377 is an apocalyptic number.

It is an amenable number.

21459812377 is a deficient number, since it is larger than the sum of its proper divisors (1).

21459812377 is an equidigital number, since it uses as much as digits as its factorization.

21459812377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 49.

The spelling of 21459812377 in words is "twenty-one billion, four hundred fifty-nine million, eight hundred twelve thousand, three hundred seventy-seven".