642796209 has 32 divisors (see below), whose sum is σ = 1056499200. Its totient is φ = 382960080.

The previous prime is 642796199. The next prime is 642796229. The reversal of 642796209 is 902697246.

It is not a de Polignac number, because 642796209 - 2⁷ = 642796081 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (642796229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 819 + ... + 35864.

It is an arithmetic number, because the mean of its divisors is an integer number (33015600).

Almost surely, 2^642796209 is an apocalyptic number.

It is an amenable number.

642796209 is a deficient number, since it is larger than the sum of its proper divisors (413702991).

642796209 is a wasteful number, since it uses less digits than its factorization.

642796209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36762 (or 36756 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 642796209 is about 25353.4259815118. The cubic root of 642796209 is about 863.0271046449.

The spelling of 642796209 in words is "six hundred forty-two million, seven hundred ninety-six thousand, two hundred nine".