641987499 has 4 divisors (see below), whose sum is σ = 855983336. Its totient is φ = 427991664.

The previous prime is 641987491. The next prime is 641987503. The reversal of 641987499 is 994789146.

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

It is not a de Polignac number, because 641987499 - 2³ = 641987491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641987491) 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 3 ways as a sum of consecutive naturals, for example, 106997914 + ... + 106997919.

It is an arithmetic number, because the mean of its divisors is an integer number (213995834).

Almost surely, 2^641987499 is an apocalyptic number.

641987499 is a deficient number, since it is larger than the sum of its proper divisors (213995837).

641987499 is a wasteful number, since it uses less digits than its factorization.

641987499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213995836.

The product of its digits is 3919104, while the sum is 57.

The square root of 641987499 is about 25337.4722298812. The cubic root of 641987499 is about 862.6650243361.

The spelling of 641987499 in words is "six hundred forty-one million, nine hundred eighty-seven thousand, four hundred ninety-nine".