646425761 has 2 divisors, whose sum is σ = 646425762. Its totient is φ = 646425760.

The previous prime is 646425737. The next prime is 646425797. The reversal of 646425761 is 167524646.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 633780625 + 12645136 = 25175^2 + 3556^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646425761 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (646425701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323212880 + 323212881.

It is an arithmetic number, because the mean of its divisors is an integer number (323212881).

Almost surely, 2^646425761 is an apocalyptic number.

It is an amenable number.

646425761 is a deficient number, since it is larger than the sum of its proper divisors (1).

646425761 is an equidigital number, since it uses as much as digits as its factorization.

646425761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 41.

The square root of 646425761 is about 25424.9043459361. The cubic root of 646425761 is about 864.6484191600.

The spelling of 646425761 in words is "six hundred forty-six million, four hundred twenty-five thousand, seven hundred sixty-one".