61697749 has 2 divisors, whose sum is σ = 61697750. Its totient is φ = 61697748.

The previous prime is 61697747. The next prime is 61697767. The reversal of 61697749 is 94779616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43362225 + 18335524 = 6585^2 + 4282^2 .

It is a cyclic number.

It is not a de Polignac number, because 61697749 - 2¹ = 61697747 is a prime.

It is a super-2 number, since 2×61697749² = 7613224463334002, which contains 22 as substring.

Together with 61697747, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61697747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30848874 + 30848875.

It is an arithmetic number, because the mean of its divisors is an integer number (30848875).

Almost surely, 2^61697749 is an apocalyptic number.

It is an amenable number.

61697749 is a deficient number, since it is larger than the sum of its proper divisors (1).

61697749 is an equidigital number, since it uses as much as digits as its factorization.

61697749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571536, while the sum is 49.

The square root of 61697749 is about 7854.7914676330. The cubic root of 61697749 is about 395.1449534761.

The spelling of 61697749 in words is "sixty-one million, six hundred ninety-seven thousand, seven hundred forty-nine".