21813914 has 4 divisors (see below), whose sum is σ = 32720874. Its totient is φ = 10906956.

The previous prime is 21813877. The next prime is 21813931. The reversal of 21813914 is 41931812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20566225 + 1247689 = 4535^2 + 1117^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5453477 + ... + 5453480.

Almost surely, 2^21813914 is an apocalyptic number.

21813914 is a deficient number, since it is larger than the sum of its proper divisors (10906960).

21813914 is a wasteful number, since it uses less digits than its factorization.

21813914 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10906959.

The product of its digits is 1728, while the sum is 29.

The square root of 21813914 is about 4670.5367999835. The cubic root of 21813914 is about 279.4116643154.

The spelling of 21813914 in words is "twenty-one million, eight hundred thirteen thousand, nine hundred fourteen".