39616561 has 2 divisors, whose sum is σ = 39616562. Its totient is φ = 39616560.

The previous prime is 39616547. The next prime is 39616571. The reversal of 39616561 is 16561693.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31528225 + 8088336 = 5615^2 + 2844^2 .

It is a cyclic number.

It is not a de Polignac number, because 39616561 - 2⁷ = 39616433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39616561.

It is not a weakly prime, because it can be changed into another prime (39616541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19808280 + 19808281.

It is an arithmetic number, because the mean of its divisors is an integer number (19808281).

Almost surely, 2^39616561 is an apocalyptic number.

It is an amenable number.

39616561 is a deficient number, since it is larger than the sum of its proper divisors (1).

39616561 is an equidigital number, since it uses as much as digits as its factorization.

39616561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29160, while the sum is 37.

The square root of 39616561 is about 6294.1688093028. The cubic root of 39616561 is about 340.8988930358.

The spelling of 39616561 in words is "thirty-nine million, six hundred sixteen thousand, five hundred sixty-one".