38713781 has 4 divisors (see below), whose sum is σ = 38739564. Its totient is φ = 38688000.

The previous prime is 38713771. The next prime is 38713793. The reversal of 38713781 is 18731783.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35509681 + 3204100 = 5959^2 + 1790^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-38713781 is a prime.

It is a super-2 number, since 2×38713781² = 2997513678631922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38713721) 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, 10490 + ... + 13691.

It is an arithmetic number, because the mean of its divisors is an integer number (9684891).

Almost surely, 2^38713781 is an apocalyptic number.

It is an amenable number.

38713781 is a deficient number, since it is larger than the sum of its proper divisors (25783).

38713781 is a wasteful number, since it uses less digits than its factorization.

38713781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25782.

The product of its digits is 28224, while the sum is 38.

The square root of 38713781 is about 6222.0399387982. The cubic root of 38713781 is about 338.2895089658.

The spelling of 38713781 in words is "thirty-eight million, seven hundred thirteen thousand, seven hundred eighty-one".