840387491 has 8 divisors (see below), whose sum is σ = 869717520. Its totient is φ = 811080928.

The previous prime is 840387487. The next prime is 840387511. The reversal of 840387491 is 194783048.

840387491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 840387491 - 2² = 840387487 is a prime.

It is a super-2 number, since 2×840387491² = 1412502270058550162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840387791) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99080 + ... + 107226.

It is an arithmetic number, because the mean of its divisors is an integer number (108714690).

Almost surely, 2^840387491 is an apocalyptic number.

840387491 is a deficient number, since it is larger than the sum of its proper divisors (29330029).

840387491 is a wasteful number, since it uses less digits than its factorization.

840387491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11733.

The product of its (nonzero) digits is 193536, while the sum is 44.

The square root of 840387491 is about 28989.4375764691. The cubic root of 840387491 is about 943.6838582011.

The spelling of 840387491 in words is "eight hundred forty million, three hundred eighty-seven thousand, four hundred ninety-one".