18931445 has 8 divisors (see below), whose sum is σ = 24465336. Its totient is φ = 13980096.

The previous prime is 18931433. The next prime is 18931499. The reversal of 18931445 is 54413981.

It can be written as a sum of positive squares in 4 ways, for example, as 1274641 + 17656804 = 1129^2 + 4202^2 .

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

It is not a de Polignac number, because 18931445 - 2¹⁶ = 18865909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145562 + ... + 145691.

It is an arithmetic number, because the mean of its divisors is an integer number (3058167).

Almost surely, 2^18931445 is an apocalyptic number.

It is an amenable number.

18931445 is a deficient number, since it is larger than the sum of its proper divisors (5533891).

18931445 is a wasteful number, since it uses less digits than its factorization.

18931445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291271.

The product of its digits is 17280, while the sum is 35.

The square root of 18931445 is about 4351.0280394408. The cubic root of 18931445 is about 266.5188442875.

The spelling of 18931445 in words is "eighteen million, nine hundred thirty-one thousand, four hundred forty-five".