38899981 has 2 divisors, whose sum is σ = 38899982. Its totient is φ = 38899980.

The previous prime is 38899967. The next prime is 38900003. The reversal of 38899981 is 18999883.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37711881 + 1188100 = 6141^2 + 1090^2 .

It is a cyclic number.

It is not a de Polignac number, because 38899981 - 2²³ = 30511373 is a prime.

It is a super-2 number, since 2×38899981² = 3026417043600722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38899951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19449990 + 19449991.

It is an arithmetic number, because the mean of its divisors is an integer number (19449991).

Almost surely, 2^38899981 is an apocalyptic number.

It is an amenable number.

38899981 is a deficient number, since it is larger than the sum of its proper divisors (1).

38899981 is an equidigital number, since it uses as much as digits as its factorization.

38899981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 55.

The square root of 38899981 is about 6236.9849286334. The cubic root of 38899981 is about 338.8309939181.

The spelling of 38899981 in words is "thirty-eight million, eight hundred ninety-nine thousand, nine hundred eighty-one".