997152181 has 2 divisors, whose sum is σ = 997152182. Its totient is φ = 997152180.

The previous prime is 997152151. The next prime is 997152239. The reversal of 997152181 is 181251799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 920151556 + 77000625 = 30334^2 + 8775^2 .

It is a cyclic number.

It is not a de Polignac number, because 997152181 - 2⁹ = 997151669 is a prime.

It is a super-2 number, since 2×997152181² = 1988624944146113522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997152151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498576090 + 498576091.

It is an arithmetic number, because the mean of its divisors is an integer number (498576091).

Almost surely, 2^997152181 is an apocalyptic number.

It is an amenable number.

997152181 is a deficient number, since it is larger than the sum of its proper divisors (1).

997152181 is an equidigital number, since it uses as much as digits as its factorization.

997152181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 43.

The square root of 997152181 is about 31577.7165260568. The cubic root of 997152181 is about 999.0498244524.

The spelling of 997152181 in words is "nine hundred ninety-seven million, one hundred fifty-two thousand, one hundred eighty-one".