21371799 has 8 divisors (see below), whose sum is σ = 28517632. Its totient is φ = 14236920.

The previous prime is 21371797. The next prime is 21371809. The reversal of 21371799 is 99717312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21371799 - 2¹ = 21371797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4722 + ... + 8064.

It is an arithmetic number, because the mean of its divisors is an integer number (3564704).

Almost surely, 2^21371799 is an apocalyptic number.

21371799 is a deficient number, since it is larger than the sum of its proper divisors (7145833).

21371799 is a wasteful number, since it uses less digits than its factorization.

21371799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5477.

The product of its digits is 23814, while the sum is 39.

The square root of 21371799 is about 4622.9643087526. The cubic root of 21371799 is about 277.5111009276.

The spelling of 21371799 in words is "twenty-one million, three hundred seventy-one thousand, seven hundred ninety-nine".