663871871 has 16 divisors (see below), whose sum is σ = 737007264. Its totient is φ = 594013824.

The previous prime is 663871867. The next prime is 663871919. The reversal of 663871871 is 178178366.

It is a cyclic number.

It is not a de Polignac number, because 663871871 - 2² = 663871867 is a prime.

It is a super-2 number, since 2×663871871² = 881451722210081282, 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 (663871841) 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, 133685 + ... + 138561.

It is an arithmetic number, because the mean of its divisors is an integer number (46062954).

Almost surely, 2^663871871 is an apocalyptic number.

663871871 is a deficient number, since it is larger than the sum of its proper divisors (73135393).

663871871 is a wasteful number, since it uses less digits than its factorization.

663871871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5210.

The product of its digits is 338688, while the sum is 47.

The square root of 663871871 is about 25765.7111487341. The cubic root of 663871871 is about 872.3580154449.

The spelling of 663871871 in words is "six hundred sixty-three million, eight hundred seventy-one thousand, eight hundred seventy-one".