648399321 has 24 divisors (see below), whose sum is σ = 954720000. Its totient is φ = 423928032.

The previous prime is 648399319. The next prime is 648399383. The reversal of 648399321 is 123993846.

It is a happy number.

It is not a de Polignac number, because 648399321 - 2¹ = 648399319 is a prime.

It is a super-2 number, since 2×648399321² = 840843358946522082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (648399391) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 269080 + ... + 271478.

It is an arithmetic number, because the mean of its divisors is an integer number (39780000).

Almost surely, 2^648399321 is an apocalyptic number.

It is an amenable number.

648399321 is a deficient number, since it is larger than the sum of its proper divisors (306320679).

648399321 is a wasteful number, since it uses less digits than its factorization.

648399321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2973 (or 2970 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 648399321 is about 25463.6863199341. The cubic root of 648399321 is about 865.5274589376.

The spelling of 648399321 in words is "six hundred forty-eight million, three hundred ninety-nine thousand, three hundred twenty-one".