39661613 has 2 divisors, whose sum is σ = 39661614. Its totient is φ = 39661612.

The previous prime is 39661603. The next prime is 39661621. The reversal of 39661613 is 31616693.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28922884 + 10738729 = 5378^2 + 3277^2 .

It is an emirp because it is prime and its reverse (31616693) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39661613 - 2⁴ = 39661597 is a prime.

It is a super-3 number, since 3×39661613³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39661603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19830806 + 19830807.

It is an arithmetic number, because the mean of its divisors is an integer number (19830807).

Almost surely, 2^39661613 is an apocalyptic number.

It is an amenable number.

39661613 is a deficient number, since it is larger than the sum of its proper divisors (1).

39661613 is an equidigital number, since it uses as much as digits as its factorization.

39661613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17496, while the sum is 35.

The square root of 39661613 is about 6297.7466605128. The cubic root of 39661613 is about 341.0280676237.

The spelling of 39661613 in words is "thirty-nine million, six hundred sixty-one thousand, six hundred thirteen".