193921997 has 2 divisors, whose sum is σ = 193921998. Its totient is φ = 193921996.

The previous prime is 193921979. The next prime is 193922017. The reversal of 193921997 is 799129391.

Together with previous prime (193921979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185477161 + 8444836 = 13619^2 + 2906^2 .

It is a cyclic number.

It is not a de Polignac number, because 193921997 - 2⁶ = 193921933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (193921597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96960998 + 96960999.

It is an arithmetic number, because the mean of its divisors is an integer number (96960999).

Almost surely, 2^193921997 is an apocalyptic number.

It is an amenable number.

193921997 is a deficient number, since it is larger than the sum of its proper divisors (1).

193921997 is an equidigital number, since it uses as much as digits as its factorization.

193921997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 275562, while the sum is 50.

The square root of 193921997 is about 13925.5878511465. The cubic root of 193921997 is about 578.8184398163.

The spelling of 193921997 in words is "one hundred ninety-three million, nine hundred twenty-one thousand, nine hundred ninety-seven".