21806774 has 8 divisors (see below), whose sum is σ = 35683848. Its totient is φ = 9912160.

The previous prime is 21806749. The next prime is 21806803. The reversal of 21806774 is 47760812.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 495587 + ... + 495630.

It is an arithmetic number, because the mean of its divisors is an integer number (4460481).

Almost surely, 2^21806774 is an apocalyptic number.

21806774 is a deficient number, since it is larger than the sum of its proper divisors (13877074).

21806774 is a wasteful number, since it uses less digits than its factorization.

21806774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991230.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 21806774 is about 4669.7723713260. The cubic root of 21806774 is about 279.3811758699.

The spelling of 21806774 in words is "twenty-one million, eight hundred six thousand, seven hundred seventy-four".