139542281 has 8 divisors (see below), whose sum is σ = 144063624. Its totient is φ = 135060480.

The previous prime is 139542199. The next prime is 139542283. The reversal of 139542281 is 182245931.

It can be written as a sum of positive squares in 4 ways, for example, as 16687225 + 122855056 = 4085^2 + 11084^2 .

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 139542281 - 2¹⁸ = 139280137 is a prime.

It is a super-2 number, since 2×139542281² = 38944096373365922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139542283) 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, 2630 + ... + 16911.

It is an arithmetic number, because the mean of its divisors is an integer number (18007953).

Almost surely, 2^139542281 is an apocalyptic number.

It is an amenable number.

139542281 is a deficient number, since it is larger than the sum of its proper divisors (4521343).

139542281 is a wasteful number, since it uses less digits than its factorization.

139542281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19771.

The product of its digits is 17280, while the sum is 35.

The square root of 139542281 is about 11812.8015728700. The cubic root of 139542281 is about 518.6829106444.

The spelling of 139542281 in words is "one hundred thirty-nine million, five hundred forty-two thousand, two hundred eighty-one".