646795871 has 8 divisors (see below), whose sum is σ = 666662688. Its totient is φ = 627228000.

The previous prime is 646795861. The next prime is 646795879. The reversal of 646795871 is 178597646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646795871 - 2²⁶ = 579687007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646795879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70340 + ... + 79001.

It is an arithmetic number, because the mean of its divisors is an integer number (83332836).

Almost surely, 2^646795871 is an apocalyptic number.

646795871 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

646795871 is a deficient number, since it is larger than the sum of its proper divisors (19866817).

646795871 is a wasteful number, since it uses less digits than its factorization.

646795871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149473.

The product of its digits is 2540160, while the sum is 53.

The square root of 646795871 is about 25432.1817978718. The cubic root of 646795871 is about 864.8134053504.

The spelling of 646795871 in words is "six hundred forty-six million, seven hundred ninety-five thousand, eight hundred seventy-one".