138102561 has 6 divisors (see below), whose sum is σ = 199481490. Its totient is φ = 92068368.

The previous prime is 138102527. The next prime is 138102563. The reversal of 138102561 is 165201831.

It can be written as a sum of positive squares in only one way, i.e., 135280161 + 2822400 = 11631^2 + 1680^2 .

It is not a de Polignac number, because 138102561 - 2⁹ = 138102049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138102563) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7672356 + ... + 7672373.

It is an arithmetic number, because the mean of its divisors is an integer number (33246915).

Almost surely, 2^138102561 is an apocalyptic number.

It is an amenable number.

138102561 is a deficient number, since it is larger than the sum of its proper divisors (61378929).

138102561 is a wasteful number, since it uses less digits than its factorization.

138102561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15344735 (or 15344732 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 138102561 is about 11751.7045997591. The cubic root of 138102561 is about 516.8929126836.

The spelling of 138102561 in words is "one hundred thirty-eight million, one hundred two thousand, five hundred sixty-one".