21976394 has 8 divisors (see below), whose sum is σ = 35961408. Its totient is φ = 9989260.

The previous prime is 21976391. The next prime is 21976399. The reversal of 21976394 is 49367912.

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

It is not an unprimeable number, because it can be changed into a prime (21976391) 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 3 ways as a sum of consecutive naturals, for example, 499442 + ... + 499485.

It is an arithmetic number, because the mean of its divisors is an integer number (4495176).

Almost surely, 2^21976394 is an apocalyptic number.

21976394 is a deficient number, since it is larger than the sum of its proper divisors (13985014).

21976394 is a wasteful number, since it uses less digits than its factorization.

21976394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 998940.

The product of its digits is 81648, while the sum is 41.

The square root of 21976394 is about 4687.8986763794. The cubic root of 21976394 is about 280.1036775922.

The spelling of 21976394 in words is "twenty-one million, nine hundred seventy-six thousand, three hundred ninety-four".