38388240901981 has 4 divisors (see below), whose sum is σ = 38530948117500. Its totient is φ = 38245533686464.

The previous prime is 38388240901859. The next prime is 38388240902059. The reversal of 38388240901981 is 18910904288383.

38388240901981 = 4381109² + 4381110².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19194116069881 + 19194124832100 = 4381109^2 + 4381110^2 .

It is a cyclic number.

It is not a de Polignac number, because 38388240901981 - 2¹⁷ = 38388240770909 is a prime.

It is a super-2 number, since 2×38388240901981² (a number of 28 digits) 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 (38388240901481) 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, 71353607356 + ... + 71353607893.

It is an arithmetic number, because the mean of its divisors is an integer number (9632737029375).

Almost surely, 2^{38388240901981} is an apocalyptic number.

38388240901981 is the 4381110-th centered square number.

It is an amenable number.

38388240901981 is a deficient number, since it is larger than the sum of its proper divisors (142707215519).

38388240901981 is a wasteful number, since it uses less digits than its factorization.

38388240901981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142707215518.

The product of its (nonzero) digits is 23887872, while the sum is 64.

The spelling of 38388240901981 in words is "thirty-eight trillion, three hundred eighty-eight billion, two hundred forty million, nine hundred one thousand, nine hundred eighty-one".