21086194 has 4 divisors (see below), whose sum is σ = 31629294. Its totient is φ = 10543096.

The previous prime is 21086179. The next prime is 21086201. The reversal of 21086194 is 49168012.

It is a happy number.

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., 20820969 + 265225 = 4563^2 + 515^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5271547 + ... + 5271550.

Almost surely, 2^21086194 is an apocalyptic number.

21086194 is a deficient number, since it is larger than the sum of its proper divisors (10543100).

21086194 is a wasteful number, since it uses less digits than its factorization.

21086194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10543099.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 21086194 is about 4591.9706009512. The cubic root of 21086194 is about 276.2693670008.

The spelling of 21086194 in words is "twenty-one million, eighty-six thousand, one hundred ninety-four".