640437369 has 64 divisors (see below), whose sum is σ = 1069867008. Its totient is φ = 335174400.

The previous prime is 640437367. The next prime is 640437373. The reversal of 640437369 is 963734046.

It is not a de Polignac number, because 640437369 - 2¹ = 640437367 is a prime.

It is a super-2 number, since 2×640437369² = 820320047223284322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640437369.

It is not an unprimeable number, because it can be changed into a prime (640437367) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 463059 + ... + 464439.

It is an arithmetic number, because the mean of its divisors is an integer number (16716672).

Almost surely, 2^640437369 is an apocalyptic number.

640437369 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

It is an amenable number.

640437369 is a deficient number, since it is larger than the sum of its proper divisors (429429639).

640437369 is a wasteful number, since it uses less digits than its factorization.

640437369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1478.

The product of its (nonzero) digits is 326592, while the sum is 42.

The square root of 640437369 is about 25306.8640688648. The cubic root of 640437369 is about 861.9701402583.

The spelling of 640437369 in words is "six hundred forty million, four hundred thirty-seven thousand, three hundred sixty-nine".