648393871 has 4 divisors (see below), whose sum is σ = 651084544. Its totient is φ = 645703200.

The previous prime is 648393859. The next prime is 648393929. The reversal of 648393871 is 178393846.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 178393846 = 2 ⋅89196923.

It is a cyclic number.

It is not a de Polignac number, because 648393871 - 2⁵ = 648393839 is a prime.

It is a super-2 number, since 2×648393871² = 840829223900729282, 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 (648393271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1344975 + ... + 1345456.

It is an arithmetic number, because the mean of its divisors is an integer number (162771136).

Almost surely, 2^648393871 is an apocalyptic number.

648393871 is a deficient number, since it is larger than the sum of its proper divisors (2690673).

648393871 is a wasteful number, since it uses less digits than its factorization.

648393871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2690672.

The product of its digits is 870912, while the sum is 49.

The square root of 648393871 is about 25463.5793045675. The cubic root of 648393871 is about 865.5250339207.

The spelling of 648393871 in words is "six hundred forty-eight million, three hundred ninety-three thousand, eight hundred seventy-one".