21173494 has 8 divisors (see below), whose sum is σ = 31873320. Its totient is φ = 10549056.

The previous prime is 21173479. The next prime is 21173497. The reversal of 21173494 is 49437112.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21173497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18139 + ... + 19270.

It is an arithmetic number, because the mean of its divisors is an integer number (3984165).

Almost surely, 2^21173494 is an apocalyptic number.

21173494 is a deficient number, since it is larger than the sum of its proper divisors (10699826).

21173494 is a wasteful number, since it uses less digits than its factorization.

21173494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37694.

The product of its digits is 6048, while the sum is 31.

The square root of 21173494 is about 4601.4665053654. The cubic root of 21173494 is about 276.6501075556.

The spelling of 21173494 in words is "twenty-one million, one hundred seventy-three thousand, four hundred ninety-four".