648931 has 2 divisors, whose sum is σ = 648932. Its totient is φ = 648930.

The previous prime is 648917. The next prime is 648937. The reversal of 648931 is 139846.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 648931 - 2⁷ = 648803 is a prime.

It is a super-2 number, since 2×648931² = 842222885522, which contains 22 as substring.

It is an Ulam number.

648931 is a lucky number.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 648893 and 648902.

It is not a weakly prime, because it can be changed into another prime (648937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324465 + 324466.

It is an arithmetic number, because the mean of its divisors is an integer number (324466).

2⁶⁴⁸⁹³¹ is an apocalyptic number.

648931 is a deficient number, since it is larger than the sum of its proper divisors (1).

648931 is an equidigital number, since it uses as much as digits as its factorization.

648931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 31.

The square root of 648931 is about 805.5625363682. The cubic root of 648931 is about 86.5763968053.

The spelling of 648931 in words is "six hundred forty-eight thousand, nine hundred thirty-one".