18421693 has 8 divisors (see below), whose sum is σ = 19700280. Its totient is φ = 17164800.

The previous prime is 18421681. The next prime is 18421709. The reversal of 18421693 is 39612481.

It can be written as a sum of positive squares in 4 ways, for example, as 12404484 + 6017209 = 3522^2 + 2453^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18421693 - 2²¹ = 16324541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18421633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3648 + ... + 7081.

It is an arithmetic number, because the mean of its divisors is an integer number (2462535).

Almost surely, 2^18421693 is an apocalyptic number.

It is an amenable number.

18421693 is a deficient number, since it is larger than the sum of its proper divisors (1278587).

18421693 is a wasteful number, since it uses less digits than its factorization.

18421693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10847.

The product of its digits is 10368, while the sum is 34.

The square root of 18421693 is about 4292.0499764099. The cubic root of 18421693 is about 264.1049332250.

The spelling of 18421693 in words is "eighteen million, four hundred twenty-one thousand, six hundred ninety-three".