196507781 has 2 divisors, whose sum is σ = 196507782. Its totient is φ = 196507780.

The previous prime is 196507757. The next prime is 196507783. The reversal of 196507781 is 187705691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128709025 + 67798756 = 11345^2 + 8234^2 .

It is a cyclic number.

It is not a de Polignac number, because 196507781 - 2²² = 192313477 is a prime.

It is a super-2 number, since 2×196507781² = 77230615987087922, which contains 22 as substring.

Together with 196507783, 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 (196507783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98253890 + 98253891.

It is an arithmetic number, because the mean of its divisors is an integer number (98253891).

Almost surely, 2^196507781 is an apocalyptic number.

It is an amenable number.

196507781 is a deficient number, since it is larger than the sum of its proper divisors (1).

196507781 is an equidigital number, since it uses as much as digits as its factorization.

196507781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 105840, while the sum is 44.

The square root of 196507781 is about 14018.1233052074. The cubic root of 196507781 is about 581.3797719109.

The spelling of 196507781 in words is "one hundred ninety-six million, five hundred seven thousand, seven hundred eighty-one".