38649781 has 8 divisors (see below), whose sum is σ = 40777280. Its totient is φ = 36531648.

The previous prime is 38649769. The next prime is 38649797. The reversal of 38649781 is 18794683.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-38649781 is a prime.

It is a super-2 number, since 2×38649781² = 2987611142695922, 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 (38649731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7165 + ... + 11341.

It is an arithmetic number, because the mean of its divisors is an integer number (5097160).

Almost surely, 2^38649781 is an apocalyptic number.

It is an amenable number.

38649781 is a deficient number, since it is larger than the sum of its proper divisors (2127499).

38649781 is a wasteful number, since it uses less digits than its factorization.

38649781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4683.

The product of its digits is 290304, while the sum is 46.

The square root of 38649781 is about 6216.8948036781. The cubic root of 38649781 is about 338.1029908013.

The spelling of 38649781 in words is "thirty-eight million, six hundred forty-nine thousand, seven hundred eighty-one".