21387703567 has 2 divisors, whose sum is σ = 21387703568. Its totient is φ = 21387703566.

The previous prime is 21387703559. The next prime is 21387703577. The reversal of 21387703567 is 76530778312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21387703567 - 2³ = 21387703559 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21387703567.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21387703507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10693851783 + 10693851784.

It is an arithmetic number, because the mean of its divisors is an integer number (10693851784).

Almost surely, 2^21387703567 is an apocalyptic number.

21387703567 is a deficient number, since it is larger than the sum of its proper divisors (1).

21387703567 is an equidigital number, since it uses as much as digits as its factorization.

21387703567 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1481760, while the sum is 49.

The spelling of 21387703567 in words is "twenty-one billion, three hundred eighty-seven million, seven hundred three thousand, five hundred sixty-seven".