172581996409 has 2 divisors, whose sum is σ = 172581996410. Its totient is φ = 172581996408.

The previous prime is 172581996277. The next prime is 172581996451. The reversal of 172581996409 is 904699185271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158782325625 + 13799670784 = 398475^2 + 117472^2 .

It is a cyclic number.

It is not a de Polignac number, because 172581996409 - 2¹³ = 172581988217 is a prime.

It is not a weakly prime, because it can be changed into another prime (172581396409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86290998204 + 86290998205.

It is an arithmetic number, because the mean of its divisors is an integer number (86290998205).

Almost surely, 2^172581996409 is an apocalyptic number.

It is an amenable number.

172581996409 is a deficient number, since it is larger than the sum of its proper divisors (1).

172581996409 is an equidigital number, since it uses as much as digits as its factorization.

172581996409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9797760, while the sum is 61.

The spelling of 172581996409 in words is "one hundred seventy-two billion, five hundred eighty-one million, nine hundred ninety-six thousand, four hundred nine".