642269717 has 4 divisors (see below), whose sum is σ = 659628396. Its totient is φ = 624911040.

The previous prime is 642269669. The next prime is 642269759. The reversal of 642269717 is 717962246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 717962246 = 2 ⋅358981123.

It can be written as a sum of positive squares in 2 ways, for example, as 339996721 + 302272996 = 18439^2 + 17386^2 .

It is a cyclic number.

It is not a de Polignac number, because 642269717 - 2⁶ = 642269653 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 (642269767) 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, 8679284 + ... + 8679357.

It is an arithmetic number, because the mean of its divisors is an integer number (164907099).

Almost surely, 2^642269717 is an apocalyptic number.

It is an amenable number.

642269717 is a deficient number, since it is larger than the sum of its proper divisors (17358679).

642269717 is a wasteful number, since it uses less digits than its factorization.

642269717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17358678.

The product of its digits is 254016, while the sum is 44.

The square root of 642269717 is about 25343.0408001881. The cubic root of 642269717 is about 862.7914151313.

The spelling of 642269717 in words is "six hundred forty-two million, two hundred sixty-nine thousand, seven hundred seventeen".