97764721 has 2 divisors, whose sum is σ = 97764722. Its totient is φ = 97764720.

The previous prime is 97764673. The next prime is 97764749. The reversal of 97764721 is 12746779.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74580496 + 23184225 = 8636^2 + 4815^2 .

It is an emirp because it is prime and its reverse (12746779) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 97764721 - 2²¹ = 95667569 is a prime.

It is not a weakly prime, because it can be changed into another prime (97764781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48882360 + 48882361.

It is an arithmetic number, because the mean of its divisors is an integer number (48882361).

Almost surely, 2^97764721 is an apocalyptic number.

It is an amenable number.

97764721 is a deficient number, since it is larger than the sum of its proper divisors (1).

97764721 is an equidigital number, since it uses as much as digits as its factorization.

97764721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 148176, while the sum is 43.

The square root of 97764721 is about 9887.6044115852. The cubic root of 97764721 is about 460.6743747560.

The spelling of 97764721 in words is "ninety-seven million, seven hundred sixty-four thousand, seven hundred twenty-one".