840404945 has 8 divisors (see below), whose sum is σ = 1067808744. Its totient is φ = 632775424.

The previous prime is 840404899. The next prime is 840404951. The reversal of 840404945 is 549404048.

It can be written as a sum of positive squares in 4 ways, for example, as 215854864 + 624550081 = 14692^2 + 24991^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 840404945 - 2¹⁴ = 840388561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 840404899 and 840404908.

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, 4943474 + ... + 4943643.

It is an arithmetic number, because the mean of its divisors is an integer number (133476093).

Almost surely, 2^840404945 is an apocalyptic number.

840404945 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

840404945 is a deficient number, since it is larger than the sum of its proper divisors (227403799).

840404945 is a wasteful number, since it uses less digits than its factorization.

840404945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9887139.

The product of its (nonzero) digits is 92160, while the sum is 38.

The square root of 840404945 is about 28989.7386155860. The cubic root of 840404945 is about 943.6903912763.

The spelling of 840404945 in words is "eight hundred forty million, four hundred four thousand, nine hundred forty-five".