139027681 has 9 divisors (see below), whose sum is σ = 150710931. Its totient is φ = 128191752.

The previous prime is 139027657. The next prime is 139027687. The reversal of 139027681 is 186720931.

The square root of 139027681 is 11791.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 20566225 + 118461456 = 4535^2 + 10884^2 .

It is not a de Polignac number, because 139027681 - 2¹¹ = 139025633 is a prime.

It is a super-2 number, since 2×139027681² = 38657392168475522, 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 139027681.

It is not an unprimeable number, because it can be changed into a prime (139027687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 152830 + ... + 153736.

It is an arithmetic number, because the mean of its divisors is an integer number (16745659).

Almost surely, 2^139027681 is an apocalyptic number.

139027681 is the 11791-st square number.

139027681 is the 5896-th centered octagonal number.

It is an amenable number.

139027681 is a deficient number, since it is larger than the sum of its proper divisors (11683250).

139027681 is an frugal number, since it uses more digits than its factorization.

139027681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1840 (or 920 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 37.

The cubic root of 139027681 is about 518.0445306400.

The spelling of 139027681 in words is "one hundred thirty-nine million, twenty-seven thousand, six hundred eighty-one".