39869861 has 2 divisors, whose sum is σ = 39869862. Its totient is φ = 39869860.

The previous prime is 39869857. The next prime is 39869881. The reversal of 39869861 is 16896893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36372961 + 3496900 = 6031^2 + 1870^2 .

It is a cyclic number.

It is not a de Polignac number, because 39869861 - 2² = 39869857 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39869821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19934930 + 19934931.

It is an arithmetic number, because the mean of its divisors is an integer number (19934931).

Almost surely, 2^39869861 is an apocalyptic number.

It is an amenable number.

39869861 is a deficient number, since it is larger than the sum of its proper divisors (1).

39869861 is an equidigital number, since it uses as much as digits as its factorization.

39869861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 50.

The square root of 39869861 is about 6314.2585471297. The cubic root of 39869861 is about 341.6238954457.

The spelling of 39869861 in words is "thirty-nine million, eight hundred sixty-nine thousand, eight hundred sixty-one".