61697729 has 2 divisors, whose sum is σ = 61697730. Its totient is φ = 61697728.

The previous prime is 61697717. The next prime is 61697747. The reversal of 61697729 is 92779616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55472704 + 6225025 = 7448^2 + 2495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61697729 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61697749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30848864 + 30848865.

It is an arithmetic number, because the mean of its divisors is an integer number (30848865).

Almost surely, 2^61697729 is an apocalyptic number.

It is an amenable number.

61697729 is a deficient number, since it is larger than the sum of its proper divisors (1).

61697729 is an equidigital number, since it uses as much as digits as its factorization.

61697729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 47.

The square root of 61697729 is about 7854.7901945246. The cubic root of 61697729 is about 395.1449107792.

It can be divided in two parts, 61697 and 729, that added together give a palindrome (62426).

The spelling of 61697729 in words is "sixty-one million, six hundred ninety-seven thousand, seven hundred twenty-nine".