139881665 has 16 divisors (see below), whose sum is σ = 209278080. Its totient is φ = 87198720.

The previous prime is 139881659. The next prime is 139881689. The reversal of 139881665 is 566188931.

It is not a de Polignac number, because 139881665 - 2⁴ = 139881649 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181280 + ... + 182049.

It is an arithmetic number, because the mean of its divisors is an integer number (13079880).

Almost surely, 2^139881665 is an apocalyptic number.

It is an amenable number.

139881665 is a deficient number, since it is larger than the sum of its proper divisors (69396415).

139881665 is a wasteful number, since it uses less digits than its factorization.

139881665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363352.

The product of its digits is 311040, while the sum is 47.

The square root of 139881665 is about 11827.1579426336. The cubic root of 139881665 is about 519.1030704248.

The spelling of 139881665 in words is "one hundred thirty-nine million, eight hundred eighty-one thousand, six hundred sixty-five".