997787729 has 2 divisors, whose sum is σ = 997787730. Its totient is φ = 997787728.

The previous prime is 997787701. The next prime is 997787741. The reversal of 997787729 is 927787799.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 540469504 + 457318225 = 23248^2 + 21385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997787729 is a prime.

It is not a weakly prime, because it can be changed into another prime (997787129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498893864 + 498893865.

It is an arithmetic number, because the mean of its divisors is an integer number (498893865).

Almost surely, 2^997787729 is an apocalyptic number.

It is an amenable number.

997787729 is a deficient number, since it is larger than the sum of its proper divisors (1).

997787729 is an equidigital number, since it uses as much as digits as its factorization.

997787729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28005264, while the sum is 65.

The square root of 997787729 is about 31587.7781586486. The cubic root of 997787729 is about 999.2620318703.

The spelling of 997787729 in words is "nine hundred ninety-seven million, seven hundred eighty-seven thousand, seven hundred twenty-nine".