869640643 has 16 divisors (see below), whose sum is σ = 900345600. Its totient is φ = 839484576.

The previous prime is 869640641. The next prime is 869640677. The reversal of 869640643 is 346046968.

It is a cyclic number.

It is not a de Polignac number, because 869640643 - 2¹ = 869640641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 869640593 and 869640602.

It is not an unprimeable number, because it can be changed into a prime (869640641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2491633 + ... + 2491981.

It is an arithmetic number, because the mean of its divisors is an integer number (56271600).

Almost surely, 2^869640643 is an apocalyptic number.

869640643 is a deficient number, since it is larger than the sum of its proper divisors (30704957).

869640643 is a wasteful number, since it uses less digits than its factorization.

869640643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 906.

The product of its (nonzero) digits is 746496, while the sum is 46.

The square root of 869640643 is about 29489.6701066662. The cubic root of 869640643 is about 954.5088134999.

The spelling of 869640643 in words is "eight hundred sixty-nine million, six hundred forty thousand, six hundred forty-three".