197388781 has 2 divisors, whose sum is σ = 197388782. Its totient is φ = 197388780.

The previous prime is 197388707. The next prime is 197388803. The reversal of 197388781 is 187883791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147403881 + 49984900 = 12141^2 + 7070^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-197388781 is a prime.

It is a super-2 number, since 2×197388781² = 77924661729331922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197382781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98694390 + 98694391.

It is an arithmetic number, because the mean of its divisors is an integer number (98694391).

Almost surely, 2^197388781 is an apocalyptic number.

It is an amenable number.

197388781 is a deficient number, since it is larger than the sum of its proper divisors (1).

197388781 is an equidigital number, since it uses as much as digits as its factorization.

197388781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 677376, while the sum is 52.

The square root of 197388781 is about 14049.5117708766. The cubic root of 197388781 is about 582.2473067536.

The spelling of 197388781 in words is "one hundred ninety-seven million, three hundred eighty-eight thousand, seven hundred eighty-one".