38581981 has 4 divisors (see below), whose sum is σ = 38614752. Its totient is φ = 38549212.

The previous prime is 38581979. The next prime is 38582003. The reversal of 38581981 is 18918583.

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.

It is a cyclic number.

It is not a de Polignac number, because 38581981 - 2¹ = 38581979 is a prime.

It is a super-2 number, since 2×38581981² = 2977138515768722, 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 (38581901) 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, 14551 + ... + 16996.

It is an arithmetic number, because the mean of its divisors is an integer number (9653688).

Almost surely, 2^38581981 is an apocalyptic number.

It is an amenable number.

38581981 is a deficient number, since it is larger than the sum of its proper divisors (32771).

38581981 is a wasteful number, since it uses less digits than its factorization.

38581981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32770.

The product of its digits is 69120, while the sum is 43.

The square root of 38581981 is about 6211.4395271950. The cubic root of 38581981 is about 337.9051733800.

The spelling of 38581981 in words is "thirty-eight million, five hundred eighty-one thousand, nine hundred eighty-one".