640108551 has 16 divisors (see below), whose sum is σ = 858933504. Its totient is φ = 424019904.

The previous prime is 640108549. The next prime is 640108571. The reversal of 640108551 is 155801046.

It is not a de Polignac number, because 640108551 - 2¹ = 640108549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640108571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 661470 + ... + 662436.

It is an arithmetic number, because the mean of its divisors is an integer number (53683344).

Almost surely, 2^640108551 is an apocalyptic number.

640108551 is a deficient number, since it is larger than the sum of its proper divisors (218824953).

640108551 is a wasteful number, since it uses less digits than its factorization.

640108551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2150.

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 640108551 is about 25300.3666178971. The cubic root of 640108551 is about 861.8225953501.

Adding to 640108551 its reverse (155801046), we get a palindrome (795909597).

The spelling of 640108551 in words is "six hundred forty million, one hundred eight thousand, five hundred fifty-one".