21949869 has 8 divisors (see below), whose sum is σ = 29288160. Its totient is φ = 14622416.

The previous prime is 21949867. The next prime is 21949871. The reversal of 21949869 is 96894912.

It is an interprime number because it is at equal distance from previous prime (21949867) and next prime (21949871).

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 21949869 - 2¹ = 21949867 is a prime.

It is a super-2 number, since 2×21949869² = 963593498234322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21949867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6319 + ... + 9155.

It is an arithmetic number, because the mean of its divisors is an integer number (3661020).

Almost surely, 2^21949869 is an apocalyptic number.

It is an amenable number.

21949869 is a deficient number, since it is larger than the sum of its proper divisors (7338291).

21949869 is a wasteful number, since it uses less digits than its factorization.

21949869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5419.

The product of its digits is 279936, while the sum is 48.

The square root of 21949869 is about 4685.0687294852. The cubic root of 21949869 is about 279.9909393327.

The spelling of 21949869 in words is "twenty-one million, nine hundred forty-nine thousand, eight hundred sixty-nine".