648447891 has 16 divisors (see below), whose sum is σ = 1064120064. Its totient is φ = 342038304.

The previous prime is 648447889. The next prime is 648447893. The reversal of 648447891 is 198744846.

648447891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (648447889) and next prime (648447893).

It is not a de Polignac number, because 648447891 - 2¹ = 648447889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (648447893) 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, 1187361 + ... + 1187906.

It is an arithmetic number, because the mean of its divisors is an integer number (66507504).

Almost surely, 2^648447891 is an apocalyptic number.

648447891 is a deficient number, since it is larger than the sum of its proper divisors (415672173).

648447891 is a wasteful number, since it uses less digits than its factorization.

648447891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2375290.

The product of its digits is 1548288, while the sum is 51.

The square root of 648447891 is about 25464.6400131634. The cubic root of 648447891 is about 865.5490699097.

The spelling of 648447891 in words is "six hundred forty-eight million, four hundred forty-seven thousand, eight hundred ninety-one".