291978 has 16 divisors (see below), whose sum is σ = 648960. Its totient is φ = 97308.

The previous prime is 291971. The next prime is 291979. The reversal of 291978 is 879192.

It is a happy number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 291978.

It is not an unprimeable number, because it can be changed into a prime (291971) 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, 2650 + ... + 2757.

It is an arithmetic number, because the mean of its divisors is an integer number (40560).

2²⁹¹⁹⁷⁸ is an apocalyptic number.

291978 is an abundant number, since it is smaller than the sum of its proper divisors (356982).

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

291978 is a wasteful number, since it uses less digits than its factorization.

291978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5418 (or 5412 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 291978 is about 540.3498866475. The cubic root of 291978 is about 66.3412081816.

The spelling of 291978 in words is "two hundred ninety-one thousand, nine hundred seventy-eight".