840642651 has 16 divisors (see below), whose sum is σ = 1246942720. Its totient is φ = 559732680.

The previous prime is 840642629. The next prime is 840642659. The reversal of 840642651 is 156246048.

840642651 is a `hidden beast` number, since 8 + 4 + 0 + 642 + 6 + 5 + 1 = 666.

It is not a de Polignac number, because 840642651 - 2⁵ = 840642619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840642659) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3306 + ... + 41136.

It is an arithmetic number, because the mean of its divisors is an integer number (77933920).

Almost surely, 2^840642651 is an apocalyptic number.

840642651 is a deficient number, since it is larger than the sum of its proper divisors (406300069).

840642651 is a wasteful number, since it uses less digits than its factorization.

840642651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38663 (or 38657 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 840642651 is about 28993.8381557185. The cubic root of 840642651 is about 943.7793562144.

Adding to 840642651 its reverse (156246048), we get a palindrome (996888699).

The spelling of 840642651 in words is "eight hundred forty million, six hundred forty-two thousand, six hundred fifty-one".