642709927 has 4 divisors (see below), whose sum is σ = 642921480. Its totient is φ = 642498376.

The previous prime is 642709909. The next prime is 642709931. The reversal of 642709927 is 729907246.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 642709927 - 2¹⁵ = 642677159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642709937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101152 + ... + 107317.

It is an arithmetic number, because the mean of its divisors is an integer number (160730370).

Almost surely, 2^642709927 is an apocalyptic number.

642709927 is a deficient number, since it is larger than the sum of its proper divisors (211553).

642709927 is a wasteful number, since it uses less digits than its factorization.

642709927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211552.

The product of its (nonzero) digits is 381024, while the sum is 46.

The square root of 642709927 is about 25351.7243397762. The cubic root of 642709927 is about 862.9884884472.

The spelling of 642709927 in words is "six hundred forty-two million, seven hundred nine thousand, nine hundred twenty-seven".