61786409 has 2 divisors, whose sum is σ = 61786410. Its totient is φ = 61786408.

The previous prime is 61786391. The next prime is 61786421. The reversal of 61786409 is 90468716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35366809 + 26419600 = 5947^2 + 5140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61786409 is a prime.

It is not a weakly prime, because it can be changed into another prime (61786429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30893204 + 30893205.

It is an arithmetic number, because the mean of its divisors is an integer number (30893205).

Almost surely, 2^61786409 is an apocalyptic number.

It is an amenable number.

61786409 is a deficient number, since it is larger than the sum of its proper divisors (1).

61786409 is an equidigital number, since it uses as much as digits as its factorization.

61786409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 61786409 is about 7860.4331305597. The cubic root of 61786409 is about 395.3341380325.

The spelling of 61786409 in words is "sixty-one million, seven hundred eighty-six thousand, four hundred nine".