646464261251 has 2 divisors, whose sum is σ = 646464261252. Its totient is φ = 646464261250.

The previous prime is 646464261229. The next prime is 646464261269. The reversal of 646464261251 is 152162464646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 646464261251 - 2⁶ = 646464261187 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 646464261196 and 646464261205.

It is not a weakly prime, because it can be changed into another prime (646464261221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323232130625 + 323232130626.

It is an arithmetic number, because the mean of its divisors is an integer number (323232130626).

Almost surely, 2^646464261251 is an apocalyptic number.

646464261251 is a deficient number, since it is larger than the sum of its proper divisors (1).

646464261251 is an equidigital number, since it uses as much as digits as its factorization.

646464261251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1658880, while the sum is 47.

The spelling of 646464261251 in words is "six hundred forty-six billion, four hundred sixty-four million, two hundred sixty-one thousand, two hundred fifty-one".