642545247 has 16 divisors (see below), whose sum is σ = 871516800. Its totient is φ = 421022112.

The previous prime is 642545237. The next prime is 642545261. The reversal of 642545247 is 742545246.

It is not a de Polignac number, because 642545247 - 2⁷ = 642545119 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642545237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42504 + ... + 55602.

It is an arithmetic number, because the mean of its divisors is an integer number (54469800).

Almost surely, 2^642545247 is an apocalyptic number.

642545247 is a deficient number, since it is larger than the sum of its proper divisors (228971553).

642545247 is a wasteful number, since it uses less digits than its factorization.

642545247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13382.

The product of its digits is 268800, while the sum is 39.

The square root of 642545247 is about 25348.4762263928. The cubic root of 642545247 is about 862.9147750045.

Subtracting 642545247 from its reverse (742545246), we obtain a palindrome (99999999).

The spelling of 642545247 in words is "six hundred forty-two million, five hundred forty-five thousand, two hundred forty-seven".