139681642 has 4 divisors (see below), whose sum is σ = 209522466. Its totient is φ = 69840820.

The previous prime is 139681621. The next prime is 139681651. The reversal of 139681642 is 246186931.

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

It can be written as a sum of positive squares in only one way, i.e., 95472441 + 44209201 = 9771^2 + 6649^2 .

It is a super-2 number, since 2×139681642² = 39021922223632328, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 139681595 and 139681604.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34920409 + ... + 34920412.

Almost surely, 2^139681642 is an apocalyptic number.

139681642 is a deficient number, since it is larger than the sum of its proper divisors (69840824).

139681642 is an equidigital number, since it uses as much as digits as its factorization.

139681642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69840823.

The product of its digits is 62208, while the sum is 40.

The square root of 139681642 is about 11818.6988285513. The cubic root of 139681642 is about 518.8555228891.

It can be divided in two parts, 1396 and 81642, that added together give a palindrome (83038).

The spelling of 139681642 in words is "one hundred thirty-nine million, six hundred eighty-one thousand, six hundred forty-two".