21086774 has 4 divisors (see below), whose sum is σ = 31630164. Its totient is φ = 10543386.

The previous prime is 21086753. The next prime is 21086839. The reversal of 21086774 is 47768012.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5271692 + ... + 5271695.

It is an arithmetic number, because the mean of its divisors is an integer number (7907541).

Almost surely, 2^21086774 is an apocalyptic number.

21086774 is a deficient number, since it is larger than the sum of its proper divisors (10543390).

21086774 is a wasteful number, since it uses less digits than its factorization.

21086774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10543389.

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

The square root of 21086774 is about 4592.0337542313. The cubic root of 21086774 is about 276.2719000130.

The spelling of 21086774 in words is "twenty-one million, eighty-six thousand, seven hundred seventy-four".