139247481 has 4 divisors (see below), whose sum is σ = 185663312. Its totient is φ = 92831652.

The previous prime is 139247467. The next prime is 139247489. The reversal of 139247481 is 184742931.

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, and also an emirpimes, since its reverse is a distinct semiprime: 184742931 = 3 ⋅61580977.

It is not a de Polignac number, because 139247481 - 2²⁶ = 72138617 is a prime.

It is a super-2 number, since 2×139247481² = 38779721929690722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139247489) 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, 23207911 + ... + 23207916.

It is an arithmetic number, because the mean of its divisors is an integer number (46415828).

Almost surely, 2^139247481 is an apocalyptic number.

It is an amenable number.

139247481 is a deficient number, since it is larger than the sum of its proper divisors (46415831).

139247481 is an equidigital number, since it uses as much as digits as its factorization.

139247481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46415830.

The product of its digits is 48384, while the sum is 39.

The square root of 139247481 is about 11800.3169872678. The cubic root of 139247481 is about 518.3173929289.

The spelling of 139247481 in words is "one hundred thirty-nine million, two hundred forty-seven thousand, four hundred eighty-one".