640159869 has 16 divisors (see below), whose sum is σ = 858642624. Its totient is φ = 424233600.

The previous prime is 640159859. The next prime is 640159873. The reversal of 640159869 is 968951046.

It is not a de Polignac number, because 640159869 - 2¹⁶ = 640094333 is a prime.

It is a super-2 number, since 2×640159869² = 819609315756194322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640159859) 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, 541459 + ... + 542639.

It is an arithmetic number, because the mean of its divisors is an integer number (53665164).

Almost surely, 2^640159869 is an apocalyptic number.

It is an amenable number.

640159869 is a deficient number, since it is larger than the sum of its proper divisors (218482755).

640159869 is a wasteful number, since it uses less digits than its factorization.

640159869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2108.

The product of its (nonzero) digits is 466560, while the sum is 48.

The square root of 640159869 is about 25301.3807725982. The cubic root of 640159869 is about 861.8456257304.

The spelling of 640159869 in words is "six hundred forty million, one hundred fifty-nine thousand, eight hundred sixty-nine".