21387703807 has 2 divisors, whose sum is σ = 21387703808. Its totient is φ = 21387703806.

The previous prime is 21387703801. The next prime is 21387703817. The reversal of 21387703807 is 70830778312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21387703807 - 2⁷ = 21387703679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21387703801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10693851903 + 10693851904.

It is an arithmetic number, because the mean of its divisors is an integer number (10693851904).

Almost surely, 2^21387703807 is an apocalyptic number.

21387703807 is a deficient number, since it is larger than the sum of its proper divisors (1).

21387703807 is an equidigital number, since it uses as much as digits as its factorization.

21387703807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 395136, while the sum is 46.

The spelling of 21387703807 in words is "twenty-one billion, three hundred eighty-seven million, seven hundred three thousand, eight hundred seven".