640003237 has 4 divisors (see below), whose sum is σ = 642313996. Its totient is φ = 637692480.

The previous prime is 640003219. The next prime is 640003241. The reversal of 640003237 is 732300046.

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

It can be written as a sum of positive squares in 2 ways, for example, as 449397601 + 190605636 = 21199^2 + 13806^2 .

It is a cyclic number.

It is not a de Polignac number, because 640003237 - 2¹⁹ = 639478949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640007237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1154964 + ... + 1155517.

It is an arithmetic number, because the mean of its divisors is an integer number (160578499).

Almost surely, 2^640003237 is an apocalyptic number.

It is an amenable number.

640003237 is a deficient number, since it is larger than the sum of its proper divisors (2310759).

640003237 is a wasteful number, since it uses less digits than its factorization.

640003237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2310758.

The product of its (nonzero) digits is 3024, while the sum is 25.

The square root of 640003237 is about 25298.2852580961. The cubic root of 640003237 is about 861.7753289072.

The spelling of 640003237 in words is "six hundred forty million, three thousand, two hundred thirty-seven".