813945 has 16 divisors (see below), whose sum is σ = 1420992. Its totient is φ = 394560.

The previous prime is 813931. The next prime is 813961. The reversal of 813945 is 549318.

It is not a de Polignac number, because 813945 - 2⁷ = 813817 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2302 + ... + 2631.

It is an arithmetic number, because the mean of its divisors is an integer number (88812).

2⁸¹³⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

813945 is a deficient number, since it is larger than the sum of its proper divisors (607047).

813945 is a wasteful number, since it uses less digits than its factorization.

813945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4952.

The product of its digits is 4320, while the sum is 30.

The square root of 813945 is about 902.1890045883. The cubic root of 813945 is about 93.3680638888.

The spelling of 813945 in words is "eight hundred thirteen thousand, nine hundred forty-five".