139635481 has 2 divisors, whose sum is σ = 139635482. Its totient is φ = 139635480.

The previous prime is 139635413. The next prime is 139635523. The reversal of 139635481 is 184536931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137358400 + 2277081 = 11720^2 + 1509^2 .

It is an emirp because it is prime and its reverse (184536931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139635481 - 2¹³ = 139627289 is a prime.

It is a super-2 number, since 2×139635481² = 38996135108202722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (139635401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69817740 + 69817741.

It is an arithmetic number, because the mean of its divisors is an integer number (69817741).

Almost surely, 2^139635481 is an apocalyptic number.

It is an amenable number.

139635481 is a deficient number, since it is larger than the sum of its proper divisors (1).

139635481 is an equidigital number, since it uses as much as digits as its factorization.

139635481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 40.

The square root of 139635481 is about 11816.7457872292. The cubic root of 139635481 is about 518.7983606920.

The spelling of 139635481 in words is "one hundred thirty-nine million, six hundred thirty-five thousand, four hundred eighty-one".