97929721 has 2 divisors, whose sum is σ = 97929722. Its totient is φ = 97929720.

The previous prime is 97929709. The next prime is 97929731. The reversal of 97929721 is 12792979.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63824121 + 34105600 = 7989^2 + 5840^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-97929721 is a prime.

It is not a weakly prime, because it can be changed into another prime (97929731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48964860 + 48964861.

It is an arithmetic number, because the mean of its divisors is an integer number (48964861).

Almost surely, 2^97929721 is an apocalyptic number.

It is an amenable number.

97929721 is a deficient number, since it is larger than the sum of its proper divisors (1).

97929721 is an equidigital number, since it uses as much as digits as its factorization.

97929721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 142884, while the sum is 46.

The square root of 97929721 is about 9895.9446744614. The cubic root of 97929721 is about 460.9333930367.

The spelling of 97929721 in words is "ninety-seven million, nine hundred twenty-nine thousand, seven hundred twenty-one".