640172037751 has 2 divisors, whose sum is σ = 640172037752. Its totient is φ = 640172037750.

The previous prime is 640172037727. The next prime is 640172037767. The reversal of 640172037751 is 157730271046.

It is a happy number.

640172037751 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640172037751 - 2¹⁷ = 640171906679 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640172037698 and 640172037707.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640172037851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320086018875 + 320086018876.

It is an arithmetic number, because the mean of its divisors is an integer number (320086018876).

Almost surely, 2^640172037751 is an apocalyptic number.

640172037751 is a deficient number, since it is larger than the sum of its proper divisors (1).

640172037751 is an equidigital number, since it uses as much as digits as its factorization.

640172037751 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 246960, while the sum is 43.

The spelling of 640172037751 in words is "six hundred forty billion, one hundred seventy-two million, thirty-seven thousand, seven hundred fifty-one".