646427042 has 4 divisors (see below), whose sum is σ = 969640566. Its totient is φ = 323213520.

The previous prime is 646427039. The next prime is 646427051. The reversal of 646427042 is 240724646.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 335292721 + 311134321 = 18311^2 + 17639^2 .

It is a junction number, because it is equal to n+sod(n) for n = 646426993 and 646427011.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161606759 + ... + 161606762.

Almost surely, 2^646427042 is an apocalyptic number.

646427042 is a deficient number, since it is larger than the sum of its proper divisors (323213524).

646427042 is a wasteful number, since it uses less digits than its factorization.

646427042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323213523.

The product of its (nonzero) digits is 64512, while the sum is 35.

The square root of 646427042 is about 25424.9295377588. The cubic root of 646427042 is about 864.6489903077.

The spelling of 646427042 in words is "six hundred forty-six million, four hundred twenty-seven thousand, forty-two".