840420169 has 4 divisors (see below), whose sum is σ = 841076496. Its totient is φ = 839763844.

The previous prime is 840420149. The next prime is 840420181. The reversal of 840420169 is 961024048.

840420169 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840420169 is a prime.

It is a super-2 number, since 2×840420169² = 1412612120923977122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840420149) 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, 326239 + ... + 328804.

It is an arithmetic number, because the mean of its divisors is an integer number (210269124).

Almost surely, 2^840420169 is an apocalyptic number.

It is an amenable number.

840420169 is a deficient number, since it is larger than the sum of its proper divisors (656327).

840420169 is a wasteful number, since it uses less digits than its factorization.

840420169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656326.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 840420169 is about 28990.0011900655. The cubic root of 840420169 is about 943.6960895831.

The spelling of 840420169 in words is "eight hundred forty million, four hundred twenty thousand, one hundred sixty-nine".