1973642221 has 2 divisors, whose sum is σ = 1973642222. Its totient is φ = 1973642220.

The previous prime is 1973642161. The next prime is 1973642261. The reversal of 1973642221 is 1222463791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1883126025 + 90516196 = 43395^2 + 9514^2 .

It is an emirp because it is prime and its reverse (1222463791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1973642221 - 2¹³ = 1973634029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1973642261) 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, 986821110 + 986821111.

It is an arithmetic number, because the mean of its divisors is an integer number (986821111).

Almost surely, 2^1973642221 is an apocalyptic number.

It is an amenable number.

1973642221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1973642221 is an equidigital number, since it uses as much as digits as its factorization.

1973642221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 37.

The square root of 1973642221 is about 44425.6932528914. The cubic root of 1973642221 is about 1254.3617694177.

The spelling of 1973642221 in words is "one billion, nine hundred seventy-three million, six hundred forty-two thousand, two hundred twenty-one".