39407681 has 4 divisors (see below), whose sum is σ = 39431364. Its totient is φ = 39384000.

The previous prime is 39407633. The next prime is 39407689. The reversal of 39407681 is 18670493.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18670493 = 3251 ⋅5743.

It can be written as a sum of positive squares in 2 ways, for example, as 2002225 + 37405456 = 1415^2 + 6116^2 .

It is a cyclic number.

It is not a de Polignac number, because 39407681 - 2¹⁸ = 39145537 is a prime.

It is a super-2 number, since 2×39407681² = 3105930643595522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39407689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9140 + ... + 12741.

It is an arithmetic number, because the mean of its divisors is an integer number (9857841).

Almost surely, 2^39407681 is an apocalyptic number.

It is an amenable number.

39407681 is a deficient number, since it is larger than the sum of its proper divisors (23683).

39407681 is a wasteful number, since it uses less digits than its factorization.

39407681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23682.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 39407681 is about 6277.5537432984. The cubic root of 39407681 is about 340.2987023236.

The spelling of 39407681 in words is "thirty-nine million, four hundred seven thousand, six hundred eighty-one".