21917814 has 8 divisors (see below), whose sum is σ = 43835640. Its totient is φ = 7305936.

The previous prime is 21917813. The next prime is 21917843. The reversal of 21917814 is 41871912.

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

21917814 is an admirable number.

It is a super-3 number, since 3×21917814³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21917813) 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, 1826479 + ... + 1826490.

It is an arithmetic number, because the mean of its divisors is an integer number (5479455).

Almost surely, 2^21917814 is an apocalyptic number.

21917814 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21917814 is a wasteful number, since it uses less digits than its factorization.

21917814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3652974.

The product of its digits is 4032, while the sum is 33.

The square root of 21917814 is about 4681.6465052372. The cubic root of 21917814 is about 279.8545758444.

The spelling of 21917814 in words is "twenty-one million, nine hundred seventeen thousand, eight hundred fourteen".