139455681 has 4 divisors (see below), whose sum is σ = 185940912. Its totient is φ = 92970452.

The previous prime is 139455677. The next prime is 139455683. The reversal of 139455681 is 186554931.

139455681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 139455681 - 2² = 139455677 is a prime.

It is a super-2 number, since 2×139455681² = 38895773926347522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (139455683) 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, 23242611 + ... + 23242616.

It is an arithmetic number, because the mean of its divisors is an integer number (46485228).

Almost surely, 2^139455681 is an apocalyptic number.

It is an amenable number.

139455681 is a deficient number, since it is larger than the sum of its proper divisors (46485231).

139455681 is an equidigital number, since it uses as much as digits as its factorization.

139455681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46485230.

The product of its digits is 129600, while the sum is 42.

The square root of 139455681 is about 11809.1354891033. The cubic root of 139455681 is about 518.5755901607.

It can be divided in two parts, 1394 and 55681, that added together give a palindrome (57075).

The spelling of 139455681 in words is "one hundred thirty-nine million, four hundred fifty-five thousand, six hundred eighty-one".