819940 has 24 divisors (see below), whose sum is σ = 1878912. Its totient is φ = 298080.

The previous prime is 819937. The next prime is 819943. The reversal of 819940 is 49918.

It is an interprime number because it is at equal distance from previous prime (819937) and next prime (819943).

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (819943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1644 + ... + 2083.

It is an arithmetic number, because the mean of its divisors is an integer number (78288).

2⁸¹⁹⁹⁴⁰ is an apocalyptic number.

It is an amenable number.

819940 is an abundant number, since it is smaller than the sum of its proper divisors (1058972).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

819940 is a wasteful number, since it uses less digits than its factorization.

819940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3747 (or 3745 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 819940 is about 905.5053837499. The cubic root of 819940 is about 93.5967332729.

The spelling of 819940 in words is "eight hundred nineteen thousand, nine hundred forty".