673187981 has 16 divisors (see below), whose sum is σ = 720861120. Its totient is φ = 626453760.

The previous prime is 673187959. The next prime is 673187987. The reversal of 673187981 is 189781376.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-673187981 is a prime.

It is a super-2 number, since 2×673187981² = 906364115525712722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (673187987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 819551 + ... + 820371.

It is an arithmetic number, because the mean of its divisors is an integer number (45053820).

Almost surely, 2^673187981 is an apocalyptic number.

It is an amenable number.

673187981 is a deficient number, since it is larger than the sum of its proper divisors (47673139).

673187981 is a wasteful number, since it uses less digits than its factorization.

673187981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324.

The product of its digits is 508032, while the sum is 50.

The square root of 673187981 is about 25945.8663567051. The cubic root of 673187981 is about 876.4196734792.

The spelling of 673187981 in words is "six hundred seventy-three million, one hundred eighty-seven thousand, nine hundred eighty-one".