641772387 has 6 divisors (see below), whose sum is σ = 927004572. Its totient is φ = 427848252.

The previous prime is 641772331. The next prime is 641772487. The reversal of 641772387 is 783277146.

It is not a de Polignac number, because 641772387 - 2¹⁵ = 641739619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (641772317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35654013 + ... + 35654030.

It is an arithmetic number, because the mean of its divisors is an integer number (154500762).

Almost surely, 2^641772387 is an apocalyptic number.

641772387 is a deficient number, since it is larger than the sum of its proper divisors (285232185).

641772387 is a wasteful number, since it uses less digits than its factorization.

641772387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71308049 (or 71308046 counting only the distinct ones).

The product of its digits is 395136, while the sum is 45.

The square root of 641772387 is about 25333.2269361801. The cubic root of 641772387 is about 862.5686619566.

It can be divided in two parts, 64177 and 2387, that added together give a square (66564 = 258²).

The spelling of 641772387 in words is "six hundred forty-one million, seven hundred seventy-two thousand, three hundred eighty-seven".