11391978 has 16 divisors (see below), whose sum is σ = 24536736. Its totient is φ = 3505200.

The previous prime is 11391977. The next prime is 11391997. The reversal of 11391978 is 87919311.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (11391977) 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, 72948 + ... + 73103.

It is an arithmetic number, because the mean of its divisors is an integer number (1533546).

Almost surely, 2^11391978 is an apocalyptic number.

11391978 is an abundant number, since it is smaller than the sum of its proper divisors (13144758).

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

11391978 is a wasteful number, since it uses less digits than its factorization.

11391978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146069.

The product of its digits is 13608, while the sum is 39.

The square root of 11391978 is about 3375.2004384925. The cubic root of 11391978 is about 225.0089082893.

The spelling of 11391978 in words is "eleven million, three hundred ninety-one thousand, nine hundred seventy-eight".