139861687 has 4 divisors (see below), whose sum is σ = 159841936. Its totient is φ = 119881440.

The previous prime is 139861663. The next prime is 139861721. The reversal of 139861687 is 786168931.

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

It is not a de Polignac number, because 139861687 - 2¹⁵ = 139828919 is a prime.

It is a super-2 number, since 2×139861687² = 39122582980971938, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 139861687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139861607) 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, 9990114 + ... + 9990127.

It is an arithmetic number, because the mean of its divisors is an integer number (39960484).

Almost surely, 2^139861687 is an apocalyptic number.

139861687 is a deficient number, since it is larger than the sum of its proper divisors (19980249).

139861687 is an equidigital number, since it uses as much as digits as its factorization.

139861687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19980248.

The product of its digits is 435456, while the sum is 49.

The square root of 139861687 is about 11826.3133308737. The cubic root of 139861687 is about 519.0783563569.

The spelling of 139861687 in words is "one hundred thirty-nine million, eight hundred sixty-one thousand, six hundred eighty-seven".