644312777051 has 2 divisors, whose sum is σ = 644312777052. Its totient is φ = 644312777050.

The previous prime is 644312776957. The next prime is 644312777083. The reversal of 644312777051 is 150777213446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644312777051 - 2¹⁴ = 644312760667 is a prime.

It is a super-3 number, since 3×644312777051³ (a number of 36 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644312776987 and 644312777005.

It is not a weakly prime, because it can be changed into another prime (644312777351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322156388525 + 322156388526.

It is an arithmetic number, because the mean of its divisors is an integer number (322156388526).

Almost surely, 2^644312777051 is an apocalyptic number.

644312777051 is a deficient number, since it is larger than the sum of its proper divisors (1).

644312777051 is an equidigital number, since it uses as much as digits as its factorization.

644312777051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 987840, while the sum is 47.

It can be divided in two parts, 64431 and 2777051, that added together give a palindrome (2841482).

The spelling of 644312777051 in words is "six hundred forty-four billion, three hundred twelve million, seven hundred seventy-seven thousand, fifty-one".