809681642 has 32 divisors (see below), whose sum is σ = 1526169600. Its totient is φ = 312968880.

The previous prime is 809681641. The next prime is 809681651. The reversal of 809681642 is 246186908.

It is a happy number.

It is a super-2 number, since 2×809681642² = 1311168722783632328, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 809681593 and 809681602.

It is not an unprimeable number, because it can be changed into a prime (809681641) 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, 1142 + ... + 40257.

It is an arithmetic number, because the mean of its divisors is an integer number (47692800).

Almost surely, 2^809681642 is an apocalyptic number.

809681642 is a deficient number, since it is larger than the sum of its proper divisors (716487958).

809681642 is a wasteful number, since it uses less digits than its factorization.

809681642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41546.

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 809681642 is about 28454.9054118969. The cubic root of 809681642 is about 932.0476108043.

The spelling of 809681642 in words is "eight hundred nine million, six hundred eighty-one thousand, six hundred forty-two".