11709978 has 16 divisors (see below), whose sum is σ = 26765760. Its totient is φ = 3345696.

The previous prime is 11709961. The next prime is 11709983. The reversal of 11709978 is 87990711.

It is a happy number.

11709978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 278809 = 11709978 / (1 + 1 + 7 + 0 + 9 + 9 + 7 + 8).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 139363 + ... + 139446.

It is an arithmetic number, because the mean of its divisors is an integer number (1672860).

Almost surely, 2^11709978 is an apocalyptic number.

11709978 is an abundant number, since it is smaller than the sum of its proper divisors (15055782).

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

11709978 is a wasteful number, since it uses less digits than its factorization.

11709978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278821.

The product of its (nonzero) digits is 31752, while the sum is 42.

The square root of 11709978 is about 3421.9845119462. The cubic root of 11709978 is about 227.0833851771.

The spelling of 11709978 in words is "eleven million, seven hundred nine thousand, nine hundred seventy-eight".