640287373 has 4 divisors (see below), whose sum is σ = 698495328. Its totient is φ = 582079420.

The previous prime is 640287353. The next prime is 640287407. The reversal of 640287373 is 373782046.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640287373 - 2²⁹ = 103416461 is a prime.

It is a super-2 number, since 2×640287373² = 819935840046482258, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640287353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29103961 + ... + 29103982.

It is an arithmetic number, because the mean of its divisors is an integer number (174623832).

Almost surely, 2^640287373 is an apocalyptic number.

It is an amenable number.

640287373 is a deficient number, since it is larger than the sum of its proper divisors (58207955).

640287373 is a wasteful number, since it uses less digits than its factorization.

640287373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58207954.

The product of its (nonzero) digits is 169344, while the sum is 40.

The square root of 640287373 is about 25303.9003515268. The cubic root of 640287373 is about 861.9028413704.

The spelling of 640287373 in words is "six hundred forty million, two hundred eighty-seven thousand, three hundred seventy-three".