2097979721 has 2 divisors, whose sum is σ = 2097979722. Its totient is φ = 2097979720.

The previous prime is 2097979711. The next prime is 2097979727. The reversal of 2097979721 is 1279797902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1560250000 + 537729721 = 39500^2 + 23189^2 .

It is a cyclic number.

It is not a de Polignac number, because 2097979721 - 2¹⁸ = 2097717577 is a prime.

It is not a weakly prime, because it can be changed into another prime (2097979727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1048989860 + 1048989861.

It is an arithmetic number, because the mean of its divisors is an integer number (1048989861).

Almost surely, 2^2097979721 is an apocalyptic number.

It is an amenable number.

2097979721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2097979721 is an equidigital number, since it uses as much as digits as its factorization.

2097979721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1000188, while the sum is 53.

The square root of 2097979721 is about 45803.7085943922. The cubic root of 2097979721 is about 1280.1683781182.

The spelling of 2097979721 in words is "two billion, ninety-seven million, nine hundred seventy-nine thousand, seven hundred twenty-one".