2391978 has 32 divisors (see below), whose sum is σ = 5054400. Its totient is φ = 753536.

The previous prime is 2391973. The next prime is 2391979. The reversal of 2391978 is 8791932.

It is not an unprimeable number, because it can be changed into a prime (2391973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10150 + ... + 10382.

It is an arithmetic number, because the mean of its divisors is an integer number (157950).

2^2391978 is an apocalyptic number.

2391978 is an abundant number, since it is smaller than the sum of its proper divisors (2662422).

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

2391978 is a wasteful number, since it uses less digits than its factorization.

2391978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326.

The product of its digits is 27216, while the sum is 39.

The square root of 2391978 is about 1546.6020819849. The cubic root of 2391978 is about 133.7372515290.

The spelling of 2391978 in words is "two million, three hundred ninety-one thousand, nine hundred seventy-eight".