138155401 has 2 divisors, whose sum is σ = 138155402. Its totient is φ = 138155400.

The previous prime is 138155393. The next prime is 138155443. The reversal of 138155401 is 104551831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90269001 + 47886400 = 9501^2 + 6920^2 .

It is a cyclic number.

It is not a de Polignac number, because 138155401 - 2³ = 138155393 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138155401.

It is not a weakly prime, because it can be changed into another prime (138155461) 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 as a sum of consecutive naturals, namely, 69077700 + 69077701.

It is an arithmetic number, because the mean of its divisors is an integer number (69077701).

Almost surely, 2^138155401 is an apocalyptic number.

It is an amenable number.

138155401 is a deficient number, since it is larger than the sum of its proper divisors (1).

138155401 is an equidigital number, since it uses as much as digits as its factorization.

138155401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 138155401 is about 11753.9525692424. The cubic root of 138155401 is about 516.9588277992.

The spelling of 138155401 in words is "one hundred thirty-eight million, one hundred fifty-five thousand, four hundred one".