61515689 has 2 divisors, whose sum is σ = 61515690. Its totient is φ = 61515688.

The previous prime is 61515683. The next prime is 61515697. The reversal of 61515689 is 98651516.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42680089 + 18835600 = 6533^2 + 4340^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61515689 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (61515683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30757844 + 30757845.

It is an arithmetic number, because the mean of its divisors is an integer number (30757845).

Almost surely, 2^61515689 is an apocalyptic number.

It is an amenable number.

61515689 is a deficient number, since it is larger than the sum of its proper divisors (1).

61515689 is an equidigital number, since it uses as much as digits as its factorization.

61515689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 41.

The square root of 61515689 is about 7843.1938009971. The cubic root of 61515689 is about 394.7559010996.

The spelling of 61515689 in words is "sixty-one million, five hundred fifteen thousand, six hundred eighty-nine".