642658065 has 32 divisors (see below), whose sum is σ = 1226244096. Its totient is φ = 281012160.

The previous prime is 642658061. The next prime is 642658099. The reversal of 642658065 is 560856246.

It is not a de Polignac number, because 642658065 - 2² = 642658061 is a prime.

It is a super-3 number, since 3×642658065³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (642658061) 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, 130641 + ... + 135470.

It is an arithmetic number, because the mean of its divisors is an integer number (38320128).

Almost surely, 2^642658065 is an apocalyptic number.

It is an amenable number.

642658065 is a deficient number, since it is larger than the sum of its proper divisors (583586031).

642658065 is a wasteful number, since it uses less digits than its factorization.

642658065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266149.

The product of its (nonzero) digits is 345600, while the sum is 42.

The square root of 642658065 is about 25350.7014695846. The cubic root of 642658065 is about 862.9652755321.

The spelling of 642658065 in words is "six hundred forty-two million, six hundred fifty-eight thousand, sixty-five".