39919409 has 2 divisors, whose sum is σ = 39919410. Its totient is φ = 39919408.

The previous prime is 39919391. The next prime is 39919423. The reversal of 39919409 is 90491993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29376400 + 10543009 = 5420^2 + 3247^2 .

It is an emirp because it is prime and its reverse (90491993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39919409 - 2¹² = 39915313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39919409.

It is not a weakly prime, because it can be changed into another prime (39919469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19959704 + 19959705.

It is an arithmetic number, because the mean of its divisors is an integer number (19959705).

Almost surely, 2^39919409 is an apocalyptic number.

It is an amenable number.

39919409 is a deficient number, since it is larger than the sum of its proper divisors (1).

39919409 is an equidigital number, since it uses as much as digits as its factorization.

39919409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 78732, while the sum is 44.

The square root of 39919409 is about 6318.1808299541. The cubic root of 39919409 is about 341.7653537913.

The spelling of 39919409 in words is "thirty-nine million, nine hundred nineteen thousand, four hundred nine".