21897794 has 8 divisors (see below), whose sum is σ = 34274880. Its totient is φ = 10472836.

The previous prime is 21897781. The next prime is 21897797. The reversal of 21897794 is 49779812.

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 (21897797) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237974 + ... + 238065.

It is an arithmetic number, because the mean of its divisors is an integer number (4284360).

Almost surely, 2^21897794 is an apocalyptic number.

21897794 is a deficient number, since it is larger than the sum of its proper divisors (12377086).

21897794 is a wasteful number, since it uses less digits than its factorization.

21897794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476064.

The product of its digits is 254016, while the sum is 47.

The square root of 21897794 is about 4679.5078801088. The cubic root of 21897794 is about 279.7693423546.

The spelling of 21897794 in words is "twenty-one million, eight hundred ninety-seven thousand, seven hundred ninety-four".