840362681 has 4 divisors (see below), whose sum is σ = 840436212. Its totient is φ = 840289152.

The previous prime is 840362671. The next prime is 840362687. The reversal of 840362681 is 186263048.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 571927225 + 268435456 = 23915^2 + 16384^2 .

It is a cyclic number.

It is not a de Polignac number, because 840362681 - 2⁶ = 840362617 is a prime.

It is a super-2 number, since 2×840362681² = 1412418871235015522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840362687) 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, 15536 + ... + 43841.

It is an arithmetic number, because the mean of its divisors is an integer number (210109053).

Almost surely, 2^840362681 is an apocalyptic number.

It is an amenable number.

840362681 is a deficient number, since it is larger than the sum of its proper divisors (73531).

840362681 is a wasteful number, since it uses less digits than its factorization.

840362681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73530.

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 840362681 is about 28989.0096588345. The cubic root of 840362681 is about 943.6745716012.

The spelling of 840362681 in words is "eight hundred forty million, three hundred sixty-two thousand, six hundred eighty-one".