139969986 has 32 divisors (see below), whose sum is σ = 301952448. Its totient is φ = 42999360.

The previous prime is 139969961. The next prime is 139969987. The reversal of 139969986 is 689969931.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (139969987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72445 + ... + 74351.

It is an arithmetic number, because the mean of its divisors is an integer number (9436014).

Almost surely, 2^139969986 is an apocalyptic number.

139969986 is an abundant number, since it is smaller than the sum of its proper divisors (161982462).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

139969986 is a wasteful number, since it uses less digits than its factorization.

139969986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2866.

The product of its digits is 5668704, while the sum is 60.

The square root of 139969986 is about 11830.8911752243. The cubic root of 139969986 is about 519.2123009812.

Subtracting 139969986 from its reverse (689969931), we obtain a palindrome (549999945).

The spelling of 139969986 in words is "one hundred thirty-nine million, nine hundred sixty-nine thousand, nine hundred eighty-six".