640265305447 has 4 divisors (see below), whose sum is σ = 640713986136. Its totient is φ = 639816624760.

The previous prime is 640265305439. The next prime is 640265305469. The reversal of 640265305447 is 744503562046.

640265305447 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 640265305447 - 2³ = 640265305439 is a prime.

It is a super-2 number, since 2×640265305447² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640265305397 and 640265305406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640265305417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 224338204 + ... + 224341057.

It is an arithmetic number, because the mean of its divisors is an integer number (160178496534).

Almost surely, 2^640265305447 is an apocalyptic number.

640265305447 is a deficient number, since it is larger than the sum of its proper divisors (448680689).

640265305447 is a wasteful number, since it uses less digits than its factorization.

640265305447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448680688.

The product of its (nonzero) digits is 2419200, while the sum is 46.

The spelling of 640265305447 in words is "six hundred forty billion, two hundred sixty-five million, three hundred five thousand, four hundred forty-seven".