646870481 has 2 divisors, whose sum is σ = 646870482. Its totient is φ = 646870480.

The previous prime is 646870381. The next prime is 646870501. The reversal of 646870481 is 184078646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 426050881 + 220819600 = 20641^2 + 14860^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646870481 is a prime.

It is a super-2 number, since 2×646870481² = 836882838378342722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (646870381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323435240 + 323435241.

It is an arithmetic number, because the mean of its divisors is an integer number (323435241).

Almost surely, 2^646870481 is an apocalyptic number.

It is an amenable number.

646870481 is a deficient number, since it is larger than the sum of its proper divisors (1).

646870481 is an equidigital number, since it uses as much as digits as its factorization.

646870481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 258048, while the sum is 44.

The square root of 646870481 is about 25433.6485978713. The cubic root of 646870481 is about 864.8466570816.

The spelling of 646870481 in words is "six hundred forty-six million, eight hundred seventy thousand, four hundred eighty-one".