17923421 has 4 divisors (see below), whose sum is σ = 18541500. Its totient is φ = 17305344.

The previous prime is 17923393. The next prime is 17923427. The reversal of 17923421 is 12432971.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13039321 + 4884100 = 3611^2 + 2210^2 .

It is not a de Polignac number, because 17923421 - 2⁶ = 17923357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 618049 = 17923421 / (1 + 7 + 9 + 2 + 3 + 4 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17923427) 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, 308996 + ... + 309053.

It is an arithmetic number, because the mean of its divisors is an integer number (4635375).

Almost surely, 2^17923421 is an apocalyptic number.

It is an amenable number.

17923421 is a deficient number, since it is larger than the sum of its proper divisors (618079).

17923421 is an equidigital number, since it uses as much as digits as its factorization.

17923421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618078.

The product of its digits is 3024, while the sum is 29.

The square root of 17923421 is about 4233.6061460651. The cubic root of 17923421 is about 261.7019560142.

The spelling of 17923421 in words is "seventeen million, nine hundred twenty-three thousand, four hundred twenty-one".