1291204478 has 8 divisors (see below), whose sum is σ = 1938621720. Its totient is φ = 644997240.

The previous prime is 1291204471. The next prime is 1291204493. The reversal of 1291204478 is 8744021921.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291204471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 299828 + ... + 304103.

It is an arithmetic number, because the mean of its divisors is an integer number (242327715).

Almost surely, 2^1291204478 is an apocalyptic number.

1291204478 is a deficient number, since it is larger than the sum of its proper divisors (647417242).

1291204478 is a wasteful number, since it uses less digits than its factorization.

1291204478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605002.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 1291204478 is about 35933.3338002474. Note that the first 3 decimals coincide. The cubic root of 1291204478 is about 1088.9259340992.

The spelling of 1291204478 in words is "one billion, two hundred ninety-one million, two hundred four thousand, four hundred seventy-eight".