21939395 has 8 divisors (see below), whose sum is σ = 27713040. Its totient is φ = 16627680.

The previous prime is 21939391. The next prime is 21939419. The reversal of 21939395 is 59393912.

It is a happy number.

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

It is not a de Polignac number, because 21939395 - 2² = 21939391 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21939391) 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, 115376 + ... + 115565.

It is an arithmetic number, because the mean of its divisors is an integer number (3464130).

Almost surely, 2^21939395 is an apocalyptic number.

21939395 is a deficient number, since it is larger than the sum of its proper divisors (5773645).

21939395 is a wasteful number, since it uses less digits than its factorization.

21939395 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230965.

The product of its digits is 65610, while the sum is 41.

The square root of 21939395 is about 4683.9507896646. The cubic root of 21939395 is about 279.9463970519.

The spelling of 21939395 in words is "twenty-one million, nine hundred thirty-nine thousand, three hundred ninety-five".