642159365 has 4 divisors (see below), whose sum is σ = 770591244. Its totient is φ = 513727488.

The previous prime is 642159347. The next prime is 642159367. The reversal of 642159365 is 563951246.

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

It can be written as a sum of positive squares in 2 ways, for example, as 360658081 + 281501284 = 18991^2 + 16778^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642159365 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642159367) 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, 64215932 + ... + 64215941.

It is an arithmetic number, because the mean of its divisors is an integer number (192647811).

Almost surely, 2^642159365 is an apocalyptic number.

It is an amenable number.

642159365 is a deficient number, since it is larger than the sum of its proper divisors (128431879).

642159365 is a wasteful number, since it uses less digits than its factorization.

642159365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128431878.

The product of its digits is 194400, while the sum is 41.

The square root of 642159365 is about 25340.8635409293. The cubic root of 642159365 is about 862.7419986068.

The spelling of 642159365 in words is "six hundred forty-two million, one hundred fifty-nine thousand, three hundred sixty-five".