21577393499 has 2 divisors, whose sum is σ = 21577393500. Its totient is φ = 21577393498.

The previous prime is 21577393469. The next prime is 21577393501. The reversal of 21577393499 is 99439377512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21577393499 is a prime.

Together with 21577393501, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21577393469) 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, 10788696749 + 10788696750.

It is an arithmetic number, because the mean of its divisors is an integer number (10788696750).

Almost surely, 2^21577393499 is an apocalyptic number.

21577393499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21577393499 is an equidigital number, since it uses as much as digits as its factorization.

21577393499 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12859560, while the sum is 59.

The spelling of 21577393499 in words is "twenty-one billion, five hundred seventy-seven million, three hundred ninety-three thousand, four hundred ninety-nine".