21387703559 has 2 divisors, whose sum is σ = 21387703560. Its totient is φ = 21387703558.

The previous prime is 21387703543. The next prime is 21387703567. The reversal of 21387703559 is 95530778312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21387703559 - 2⁴ = 21387703543 is a prime.

It is a super-2 number, since 2×21387703559² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21387703159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10693851779 + 10693851780.

It is an arithmetic number, because the mean of its divisors is an integer number (10693851780).

Almost surely, 2^21387703559 is an apocalyptic number.

21387703559 is a deficient number, since it is larger than the sum of its proper divisors (1).

21387703559 is an equidigital number, since it uses as much as digits as its factorization.

21387703559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1587600, while the sum is 50.

The spelling of 21387703559 in words is "twenty-one billion, three hundred eighty-seven million, seven hundred three thousand, five hundred fifty-nine".