21248599 has 2 divisors, whose sum is σ = 21248600. Its totient is φ = 21248598.

The previous prime is 21248597. The next prime is 21248639. The reversal of 21248599 is 99584212.

It is an a-pointer prime, because the next prime (21248639) can be obtained adding 21248599 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21248599 - 2¹ = 21248597 is a prime.

Together with 21248597, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21248597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10624299 + 10624300.

It is an arithmetic number, because the mean of its divisors is an integer number (10624300).

Almost surely, 2^21248599 is an apocalyptic number.

21248599 is a deficient number, since it is larger than the sum of its proper divisors (1).

21248599 is an equidigital number, since it uses as much as digits as its factorization.

21248599 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 40.

The square root of 21248599 is about 4609.6202663560. The cubic root of 21248599 is about 276.9768255971.

The spelling of 21248599 in words is "twenty-one million, two hundred forty-eight thousand, five hundred ninety-nine".