2192187721 has 2 divisors, whose sum is σ = 2192187722. Its totient is φ = 2192187720.

The previous prime is 2192187709. The next prime is 2192187731. The reversal of 2192187721 is 1277812912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1379082496 + 813105225 = 37136^2 + 28515^2 .

It is a cyclic number.

It is not a de Polignac number, because 2192187721 - 2⁷ = 2192187593 is a prime.

It is not a weakly prime, because it can be changed into another prime (2192187731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1096093860 + 1096093861.

It is an arithmetic number, because the mean of its divisors is an integer number (1096093861).

Almost surely, 2^2192187721 is an apocalyptic number.

It is an amenable number.

2192187721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2192187721 is an equidigital number, since it uses as much as digits as its factorization.

2192187721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 40.

The square root of 2192187721 is about 46820.8043608821. The cubic root of 2192187721 is about 1299.0501386853.

The spelling of 2192187721 in words is "two billion, one hundred ninety-two million, one hundred eighty-seven thousand, seven hundred twenty-one".