61566997 has 2 divisors, whose sum is σ = 61566998. Its totient is φ = 61566996.

The previous prime is 61566977. The next prime is 61567003. The reversal of 61566997 is 79966516.

61566997 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31820881 + 29746116 = 5641^2 + 5454^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61566997 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61566997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61566937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30783498 + 30783499.

It is an arithmetic number, because the mean of its divisors is an integer number (30783499).

Almost surely, 2^61566997 is an apocalyptic number.

It is an amenable number.

61566997 is a deficient number, since it is larger than the sum of its proper divisors (1).

61566997 is an equidigital number, since it uses as much as digits as its factorization.

61566997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 612360, while the sum is 49.

The square root of 61566997 is about 7846.4639806731. The cubic root of 61566997 is about 394.8656211164.

The spelling of 61566997 in words is "sixty-one million, five hundred sixty-six thousand, nine hundred ninety-seven".