39121561 has 2 divisors, whose sum is σ = 39121562. Its totient is φ = 39121560.

The previous prime is 39121553. The next prime is 39121591. The reversal of 39121561 is 16512193.

39121561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32262400 + 6859161 = 5680^2 + 2619^2 .

It is an emirp because it is prime and its reverse (16512193) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39121561 - 2³ = 39121553 is a prime.

It is not a weakly prime, because it can be changed into another prime (39121591) 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, 19560780 + 19560781.

It is an arithmetic number, because the mean of its divisors is an integer number (19560781).

Almost surely, 2^39121561 is an apocalyptic number.

It is an amenable number.

39121561 is a deficient number, since it is larger than the sum of its proper divisors (1).

39121561 is an equidigital number, since it uses as much as digits as its factorization.

39121561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 28.

The square root of 39121561 is about 6254.7230953896. The cubic root of 39121561 is about 339.4731199296.

It can be divided in two parts, 391 and 21561, that added together give a cube (21952 = 28³).

The spelling of 39121561 in words is "thirty-nine million, one hundred twenty-one thousand, five hundred sixty-one".