640034551 has 8 divisors (see below), whose sum is σ = 725545520. Its totient is φ = 559706112.

The previous prime is 640034539. The next prime is 640034561. The reversal of 640034551 is 155430046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640034551 - 2¹⁷ = 639903479 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 (640034561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1295370 + ... + 1295863.

It is an arithmetic number, because the mean of its divisors is an integer number (90693190).

Almost surely, 2^640034551 is an apocalyptic number.

640034551 is a deficient number, since it is larger than the sum of its proper divisors (85510969).

640034551 is a wasteful number, since it uses less digits than its factorization.

640034551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2591265.

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 640034551 is about 25298.9041462274. The cubic root of 640034551 is about 861.7893836239.

Adding to 640034551 its reverse (155430046), we get a palindrome (795464597).

The spelling of 640034551 in words is "six hundred forty million, thirty-four thousand, five hundred fifty-one".