806640642 has 48 divisors (see below), whose sum is σ = 1810612440. Its totient is φ = 259353600.

The previous prime is 806640617. The next prime is 806640647. The reversal of 806640642 is 246046608.

It is a happy number.

806640642 is a `hidden beast` number, since 8 + 0 + 6 + 6 + 4 + 0 + 642 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 527115681 + 279524961 = 22959^2 + 16719^2 .

It is a junction number, because it is equal to n+sod(n) for n = 806640597 and 806640606.

It is not an unprimeable number, because it can be changed into a prime (806640647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 59542 + ... + 71822.

Almost surely, 2^806640642 is an apocalyptic number.

806640642 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

806640642 is an abundant number, since it is smaller than the sum of its proper divisors (1003971798).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

806640642 is a wasteful number, since it uses less digits than its factorization.

806640642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12419 (or 12416 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 806640642 is about 28401.4197180352. The cubic root of 806640642 is about 930.8792863326.

The spelling of 806640642 in words is "eight hundred six million, six hundred forty thousand, six hundred forty-two".