640862845 has 16 divisors (see below), whose sum is σ = 907250688. Its totient is φ = 425272320.

The previous prime is 640862843. The next prime is 640862861. The reversal of 640862845 is 548268046.

It is not a de Polignac number, because 640862845 - 2¹ = 640862843 is a prime.

It is a super-2 number, since 2×640862845² = 821410372202988050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640862843) 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, 294244 + ... + 296413.

It is an arithmetic number, because the mean of its divisors is an integer number (56703168).

Almost surely, 2^640862845 is an apocalyptic number.

It is an amenable number.

640862845 is a deficient number, since it is larger than the sum of its proper divisors (266387843).

640862845 is a wasteful number, since it uses less digits than its factorization.

640862845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590700.

The product of its (nonzero) digits is 368640, while the sum is 43.

The square root of 640862845 is about 25315.2690090388. The cubic root of 640862845 is about 862.1609819334.

The spelling of 640862845 in words is "six hundred forty million, eight hundred sixty-two thousand, eight hundred forty-five".