21002199 has 16 divisors (see below), whose sum is σ = 28892160. Its totient is φ = 13560480.

The previous prime is 21002129. The next prime is 21002203. The reversal of 21002199 is 99120012.

It is not a de Polignac number, because 21002199 - 2⁸ = 21001943 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47622 + ... + 48060.

It is an arithmetic number, because the mean of its divisors is an integer number (1805760).

Almost surely, 2^21002199 is an apocalyptic number.

21002199 is a deficient number, since it is larger than the sum of its proper divisors (7889961).

21002199 is a wasteful number, since it uses less digits than its factorization.

21002199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 21002199 is about 4582.8156192454. The cubic root of 21002199 is about 275.9020472611.

The spelling of 21002199 in words is "twenty-one million, two thousand, one hundred ninety-nine".