644462051 has 2 divisors, whose sum is σ = 644462052. Its totient is φ = 644462050.

The previous prime is 644462029. The next prime is 644462089. The reversal of 644462051 is 150264446.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644462051 is a prime.

It is a Chen prime.

It is equal to p_33520298 and since 644462051 and 33520298 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 644461999 and 644462017.

It is not a weakly prime, because it can be changed into another prime (644462551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322231025 + 322231026.

It is an arithmetic number, because the mean of its divisors is an integer number (322231026).

Almost surely, 2^644462051 is an apocalyptic number.

644462051 is a deficient number, since it is larger than the sum of its proper divisors (1).

644462051 is an equidigital number, since it uses as much as digits as its factorization.

644462051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 644462051 is about 25386.2571286119. The cubic root of 644462051 is about 863.7719890691.

The spelling of 644462051 in words is "six hundred forty-four million, four hundred sixty-two thousand, fifty-one".