21598807 has 2 divisors, whose sum is σ = 21598808. Its totient is φ = 21598806.

The previous prime is 21598783. The next prime is 21598849. The reversal of 21598807 is 70889512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21598807 - 2¹⁹ = 21074519 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21598807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21598207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10799403 + 10799404.

It is an arithmetic number, because the mean of its divisors is an integer number (10799404).

Almost surely, 2^21598807 is an apocalyptic number.

21598807 is a deficient number, since it is larger than the sum of its proper divisors (1).

21598807 is an equidigital number, since it uses as much as digits as its factorization.

21598807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 21598807 is about 4647.4516673119. The cubic root of 21598807 is about 278.4902026858.

The spelling of 21598807 in words is "twenty-one million, five hundred ninety-eight thousand, eight hundred seven".