21941999 has 8 divisors (see below), whose sum is σ = 22667760. Its totient is φ = 21223296.

The previous prime is 21941993. The next prime is 21942007. The reversal of 21941999 is 99914912.

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

It is a cyclic number.

It is not a de Polignac number, because 21941999 - 2⁸ = 21941743 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 (21941993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4967 + ... + 8279.

It is an arithmetic number, because the mean of its divisors is an integer number (2833470).

Almost surely, 2^21941999 is an apocalyptic number.

21941999 is a deficient number, since it is larger than the sum of its proper divisors (725761).

21941999 is a wasteful number, since it uses less digits than its factorization.

21941999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3529.

The product of its digits is 52488, while the sum is 44.

The square root of 21941999 is about 4684.2287518865. The cubic root of 21941999 is about 279.9574722825.

The spelling of 21941999 in words is "twenty-one million, nine hundred forty-one thousand, nine hundred ninety-nine".