640520401242 has 32 divisors (see below), whose sum is σ = 1299564812160. Its totient is φ = 210421693440.

The previous prime is 640520401219. The next prime is 640520401243. The reversal of 640520401242 is 242104025046.

It is not an unprimeable number, because it can be changed into a prime (640520401243) 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, 878634 + ... + 1432842.

It is an arithmetic number, because the mean of its divisors is an integer number (40611400380).

Almost surely, 2^640520401242 is an apocalyptic number.

640520401242 is an abundant number, since it is smaller than the sum of its proper divisors (659044410918).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640520401242 is a wasteful number, since it uses less digits than its factorization.

640520401242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556998.

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 640520401242 its reverse (242104025046), we get a palindrome (882624426288).

The spelling of 640520401242 in words is "six hundred forty billion, five hundred twenty million, four hundred one thousand, two hundred forty-two".