1971901 has 2 divisors, whose sum is σ = 1971902. Its totient is φ = 1971900.

The previous prime is 1971889. The next prime is 1971911. The reversal of 1971901 is 1091791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1819801 + 152100 = 1349^2 + 390^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971901 - 2⁵ = 1971869 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1971901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1971911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985950 + 985951.

It is an arithmetic number, because the mean of its divisors is an integer number (985951).

2^1971901 is an apocalyptic number.

It is an amenable number.

1971901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971901 is an equidigital number, since it uses as much as digits as its factorization.

1971901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 567, while the sum is 28.

The square root of 1971901 is about 1404.2439246798. The cubic root of 1971901 is about 125.3992779258.

The spelling of 1971901 in words is "one million, nine hundred seventy-one thousand, nine hundred one".