138489525 has 18 divisors (see below), whose sum is σ = 248050530. Its totient is φ = 73860960.

The previous prime is 138489521. The next prime is 138489551. The reversal of 138489525 is 525984831.

It can be written as a sum of positive squares in 3 ways, for example, as 30371121 + 108118404 = 5511^2 + 10398^2 .

It is not a de Polignac number, because 138489525 - 2² = 138489521 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138489521) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 307530 + ... + 307979.

It is an arithmetic number, because the mean of its divisors is an integer number (13780585).

Almost surely, 2^138489525 is an apocalyptic number.

138489525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138489525 is a deficient number, since it is larger than the sum of its proper divisors (109561005).

138489525 is a wasteful number, since it uses less digits than its factorization.

138489525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615525 (or 615517 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 138489525 is about 11768.1572474198. The cubic root of 138489525 is about 517.3752412271.

It can be divided in two parts, 1384 and 89525, that added together give a palindrome (90909).

The spelling of 138489525 in words is "one hundred thirty-eight million, four hundred eighty-nine thousand, five hundred twenty-five".