745991 has 4 divisors (see below), whose sum is σ = 747792. Its totient is φ = 744192.

The previous prime is 745981. The next prime is 745993. The reversal of 745991 is 199547.

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

It is a cyclic number.

It is not a de Polignac number, because 745991 - 2¹⁴ = 729607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (745993) 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, 71 + ... + 1223.

It is an arithmetic number, because the mean of its divisors is an integer number (186948).

2⁷⁴⁵⁹⁹¹ is an apocalyptic number.

745991 is a deficient number, since it is larger than the sum of its proper divisors (1801).

745991 is a wasteful number, since it uses less digits than its factorization.

745991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800.

The product of its digits is 11340, while the sum is 35.

The square root of 745991 is about 863.7077051874. The cubic root of 745991 is about 90.6938550838.

The spelling of 745991 in words is "seven hundred forty-five thousand, nine hundred ninety-one".