648638331 has 16 divisors (see below), whose sum is σ = 976008960. Its totient is φ = 379557920.

The previous prime is 648638303. The next prime is 648638363. The reversal of 648638331 is 133836846.

It is a cyclic number.

It is not a de Polignac number, because 648638331 - 2¹³ = 648630139 is a prime.

It is a super-2 number, since 2×648638331² = 841463368884931122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (648638371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 337935 + ... + 339848.

It is an arithmetic number, because the mean of its divisors is an integer number (61000560).

Almost surely, 2^648638331 is an apocalyptic number.

648638331 is a deficient number, since it is larger than the sum of its proper divisors (327370629).

648638331 is a wasteful number, since it uses less digits than its factorization.

648638331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677826.

The product of its digits is 248832, while the sum is 42.

The square root of 648638331 is about 25468.3790414702. The cubic root of 648638331 is about 865.6337948009.

The spelling of 648638331 in words is "six hundred forty-eight million, six hundred thirty-eight thousand, three hundred thirty-one".