21806734 has 8 divisors (see below), whose sum is σ = 32747688. Its totient is φ = 10890840.

The previous prime is 21806723. The next prime is 21806749. The reversal of 21806734 is 43760812.

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

It is a junction number, because it is equal to n+sod(n) for n = 21806696 and 21806705.

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, 3912 + ... + 7675.

It is an arithmetic number, because the mean of its divisors is an integer number (4093461).

Almost surely, 2^21806734 is an apocalyptic number.

21806734 is a deficient number, since it is larger than the sum of its proper divisors (10940954).

21806734 is a wasteful number, since it uses less digits than its factorization.

21806734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12530.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21806734 is about 4669.7680884601. The cubic root of 21806734 is about 279.3810050475.

The spelling of 21806734 in words is "twenty-one million, eight hundred six thousand, seven hundred thirty-four".