189181397 has 2 divisors, whose sum is σ = 189181398. Its totient is φ = 189181396.

The previous prime is 189181373. The next prime is 189181403. The reversal of 189181397 is 793181981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167288356 + 21893041 = 12934^2 + 4679^2 .

It is a cyclic number.

It is not a de Polignac number, because 189181397 - 2¹² = 189177301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189181357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94590698 + 94590699.

It is an arithmetic number, because the mean of its divisors is an integer number (94590699).

Almost surely, 2^189181397 is an apocalyptic number.

It is an amenable number.

189181397 is a deficient number, since it is larger than the sum of its proper divisors (1).

189181397 is an equidigital number, since it uses as much as digits as its factorization.

189181397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 47.

The square root of 189181397 is about 13754.3228477450. The cubic root of 189181397 is about 574.0628939975.

The spelling of 189181397 in words is "one hundred eighty-nine million, one hundred eighty-one thousand, three hundred ninety-seven".