38921781 has 8 divisors (see below), whose sum is σ = 53000064. Its totient is φ = 25395680.

The previous prime is 38921777. The next prime is 38921783. The reversal of 38921781 is 18712983.

38921781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 38921781 - 2² = 38921777 is a prime.

It is a super-2 number, since 2×38921781² = 3029810072423922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38921783) 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 7 ways as a sum of consecutive naturals, for example, 137880 + ... + 138161.

It is an arithmetic number, because the mean of its divisors is an integer number (6625008).

Almost surely, 2^38921781 is an apocalyptic number.

It is an amenable number.

38921781 is a deficient number, since it is larger than the sum of its proper divisors (14078283).

38921781 is a wasteful number, since it uses less digits than its factorization.

38921781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276091.

The product of its digits is 24192, while the sum is 39.

The square root of 38921781 is about 6238.7323231567. The cubic root of 38921781 is about 338.8942770362.

The spelling of 38921781 in words is "thirty-eight million, nine hundred twenty-one thousand, seven hundred eighty-one".