1939198901 has 2 divisors, whose sum is σ = 1939198902. Its totient is φ = 1939198900.

The previous prime is 1939198873. The next prime is 1939198909. The reversal of 1939198901 is 1098919391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1889988676 + 49210225 = 43474^2 + 7015^2 .

It is an emirp because it is prime and its reverse (1098919391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1939198901 - 2⁶ = 1939198837 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1939198901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1939198909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 969599450 + 969599451.

It is an arithmetic number, because the mean of its divisors is an integer number (969599451).

Almost surely, 2^1939198901 is an apocalyptic number.

It is an amenable number.

1939198901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1939198901 is an equidigital number, since it uses as much as digits as its factorization.

1939198901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 50.

The square root of 1939198901 is about 44036.3361441435. The cubic root of 1939198901 is about 1247.0220097735.

The spelling of 1939198901 in words is "one billion, nine hundred thirty-nine million, one hundred ninety-eight thousand, nine hundred one".