21170194 has 8 divisors (see below), whose sum is σ = 31958028. Its totient is φ = 10517520.

The previous prime is 21170159. The next prime is 21170207. The reversal of 21170194 is 49107112.

It can be written as a sum of positive squares in 2 ways, for example, as 21114025 + 56169 = 4595^2 + 237^2 .

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

It is a super-2 number, since 2×21170194² = 896354227995272, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33397 + ... + 34024.

Almost surely, 2^21170194 is an apocalyptic number.

21170194 is a deficient number, since it is larger than the sum of its proper divisors (10787834).

21170194 is a wasteful number, since it uses less digits than its factorization.

21170194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67580.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 21170194 is about 4601.1079100582. The cubic root of 21170194 is about 276.6357343525.

The spelling of 21170194 in words is "twenty-one million, one hundred seventy thousand, one hundred ninety-four".