138447481 has 8 divisors (see below), whose sum is σ = 140019264. Its totient is φ = 136883760.

The previous prime is 138447461. The next prime is 138447497. The reversal of 138447481 is 184744831.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138447481 is a prime.

It is a super-2 number, since 2×138447481² = 38335409990490722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138447461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36580 + ... + 40186.

It is an arithmetic number, because the mean of its divisors is an integer number (17502408).

Almost surely, 2^138447481 is an apocalyptic number.

It is an amenable number.

138447481 is a deficient number, since it is larger than the sum of its proper divisors (1571783).

138447481 is a wasteful number, since it uses less digits than its factorization.

138447481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4031.

The product of its digits is 86016, while the sum is 40.

The square root of 138447481 is about 11766.3707658734. The cubic root of 138447481 is about 517.3228793216.

The spelling of 138447481 in words is "one hundred thirty-eight million, four hundred forty-seven thousand, four hundred eighty-one".