642440365 has 16 divisors (see below), whose sum is σ = 884759040. Its totient is φ = 438681600.

The previous prime is 642440363. The next prime is 642440371. The reversal of 642440365 is 563044246.

It is not a de Polignac number, because 642440365 - 2¹ = 642440363 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642440365.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642440363) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30036 + ... + 46765.

It is an arithmetic number, because the mean of its divisors is an integer number (55297440).

Almost surely, 2^642440365 is an apocalyptic number.

It is an amenable number.

642440365 is a deficient number, since it is larger than the sum of its proper divisors (242318675).

642440365 is a wasteful number, since it uses less digits than its factorization.

642440365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77052.

The product of its (nonzero) digits is 69120, while the sum is 34.

The square root of 642440365 is about 25346.4073391082. The cubic root of 642440365 is about 862.8678215525.

The spelling of 642440365 in words is "six hundred forty-two million, four hundred forty thousand, three hundred sixty-five".