640267227889 has 9 divisors (see below), whose sum is σ = 644350605003. Its totient is φ = 636209581032.

The previous prime is 640267227871. The next prime is 640267227913. The reversal of 640267227889 is 988722762046.

The square root of 640267227889 is 800167.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 635580456289 + 4686771600 = 797233^2 + 68460^2 .

It is not a de Polignac number, because 640267227889 - 2²³ = 640258839281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640267227689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 130424767 + ... + 130429675.

It is an arithmetic number, because the mean of its divisors is an integer number (71594511667).

Almost surely, 2^640267227889 is an apocalyptic number.

640267227889 is the 800167-th square number.

640267227889 is the 400084-th centered octagonal number.

It is an amenable number.

640267227889 is a deficient number, since it is larger than the sum of its proper divisors (4083377114).

640267227889 is an frugal number, since it uses more digits than its factorization.

640267227889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10144 (or 5072 counting only the distinct ones).

The product of its (nonzero) digits is 32514048, while the sum is 61.

The spelling of 640267227889 in words is "six hundred forty billion, two hundred sixty-seven million, two hundred twenty-seven thousand, eight hundred eighty-nine".