840698921 has 8 divisors (see below), whose sum is σ = 877856640. Its totient is φ = 803591712.

The previous prime is 840698897. The next prime is 840698923. The reversal of 840698921 is 129896048.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840698921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (840698923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23645 + ... + 47333.

It is an arithmetic number, because the mean of its divisors is an integer number (109732080).

Almost surely, 2^840698921 is an apocalyptic number.

It is an amenable number.

840698921 is a deficient number, since it is larger than the sum of its proper divisors (37157719).

840698921 is a wasteful number, since it uses less digits than its factorization.

840698921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25255.

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 840698921 is about 28994.8085180779. The cubic root of 840698921 is about 943.8004136279.

The spelling of 840698921 in words is "eight hundred forty million, six hundred ninety-eight thousand, nine hundred twenty-one".