745681 has 4 divisors (see below), whose sum is σ = 755200. Its totient is φ = 736164.

The previous prime is 745673. The next prime is 745697. The reversal of 745681 is 186547.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 186547 = 101 ⋅1847.

It is a cyclic number.

It is not a de Polignac number, because 745681 - 2³ = 745673 is a prime.

It is a super-2 number, since 2×745681² = 1112080307522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (745601) 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, 4641 + ... + 4798.

It is an arithmetic number, because the mean of its divisors is an integer number (188800).

2⁷⁴⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

745681 is a deficient number, since it is larger than the sum of its proper divisors (9519).

745681 is an equidigital number, since it uses as much as digits as its factorization.

745681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9518.

The product of its digits is 6720, while the sum is 31.

The square root of 745681 is about 863.5282276799. The cubic root of 745681 is about 90.6812905934.

The spelling of 745681 in words is "seven hundred forty-five thousand, six hundred eighty-one".