1391904 has 72 divisors (see below), whose sum is σ = 4127760. Its totient is φ = 461376.

The previous prime is 1391899. The next prime is 1391917. The reversal of 1391904 is 4091931.

1391904 = T₂₄ + T₂₅ + ... + T₂₀₂.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7687 + ... + 7865.

It is an arithmetic number, because the mean of its divisors is an integer number (57330).

2^1391904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1391904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2063880).

1391904 is an abundant number, since it is smaller than the sum of its proper divisors (2735856).

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

1391904 is an equidigital number, since it uses as much as digits as its factorization.

1391904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 1391904 is about 1179.7898117885. The cubic root of 1391904 is about 111.6528365833.

Adding to 1391904 its sum of digits (27), we get a palindrome (1391931).

The spelling of 1391904 in words is "one million, three hundred ninety-one thousand, nine hundred four".