172901720639 has 2 divisors, whose sum is σ = 172901720640. Its totient is φ = 172901720638.

The previous prime is 172901720627. The next prime is 172901720683. The reversal of 172901720639 is 936027109271.

It is a weak prime.

It is an emirp because it is prime and its reverse (936027109271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172901720639 - 2⁴ = 172901720623 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 172901720593 and 172901720602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172901720839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86450860319 + 86450860320.

It is an arithmetic number, because the mean of its divisors is an integer number (86450860320).

Almost surely, 2^172901720639 is an apocalyptic number.

172901720639 is a deficient number, since it is larger than the sum of its proper divisors (1).

172901720639 is an equidigital number, since it uses as much as digits as its factorization.

172901720639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 285768, while the sum is 47.

The spelling of 172901720639 in words is "one hundred seventy-two billion, nine hundred one million, seven hundred twenty thousand, six hundred thirty-nine".