172160981 has 2 divisors, whose sum is σ = 172160982. Its totient is φ = 172160980.

The previous prime is 172160969. The next prime is 172160983. The reversal of 172160981 is 189061271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125238481 + 46922500 = 11191^2 + 6850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172160981 is a prime.

It is a super-2 number, since 2×172160981² = 59278806757764722, which contains 22 as substring.

Together with 172160983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172160983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86080490 + 86080491.

It is an arithmetic number, because the mean of its divisors is an integer number (86080491).

Almost surely, 2^172160981 is an apocalyptic number.

It is an amenable number.

172160981 is a deficient number, since it is larger than the sum of its proper divisors (1).

172160981 is an equidigital number, since it uses as much as digits as its factorization.

172160981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 35.

The square root of 172160981 is about 13121.0129563232. The cubic root of 172160981 is about 556.3032231866.

The spelling of 172160981 in words is "one hundred seventy-two million, one hundred sixty thousand, nine hundred eighty-one".