38180721 has 4 divisors (see below), whose sum is σ = 50907632. Its totient is φ = 25453812.

The previous prime is 38180711. The next prime is 38180731. The reversal of 38180721 is 12708183.

It is a happy number.

38180721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12708183 = 3 ⋅4236061.

It is an interprime number because it is at equal distance from previous prime (38180711) and next prime (38180731).

It is not a de Polignac number, because 38180721 - 2⁹ = 38180209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (38180711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6363451 + ... + 6363456.

It is an arithmetic number, because the mean of its divisors is an integer number (12726908).

Almost surely, 2^38180721 is an apocalyptic number.

It is an amenable number.

38180721 is a deficient number, since it is larger than the sum of its proper divisors (12726911).

38180721 is a wasteful number, since it uses less digits than its factorization.

38180721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12726910.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 38180721 is about 6179.0550248400. The cubic root of 38180721 is about 336.7296625356.

Subtracting from 38180721 its sum of digits (30), we obtain a triangular number (38180691 = T₈₇₃₈).

The spelling of 38180721 in words is "thirty-eight million, one hundred eighty thousand, seven hundred twenty-one".