1291904 has 16 divisors (see below), whose sum is σ = 2573970. Its totient is φ = 645888.

The previous prime is 1291883. The next prime is 1291907. The reversal of 1291904 is 4091921.

It can be written as a sum of positive squares in only one way, i.e., 1098304 + 193600 = 1048^2 + 440^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is not an unprimeable number, because it can be changed into a prime (1291907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4919 + ... + 5174.

2^1291904 is an apocalyptic number.

It is an amenable number.

1291904 is a deficient number, since it is larger than the sum of its proper divisors (1282066).

1291904 is an equidigital number, since it uses as much as digits as its factorization.

1291904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10107 (or 10095 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 1291904 is about 1136.6195493656. The cubic root of 1291904 is about 108.9122543839.

The spelling of 1291904 in words is "one million, two hundred ninety-one thousand, nine hundred four".