138565553 has 4 divisors (see below), whose sum is σ = 158360640. Its totient is φ = 118770468.

The previous prime is 138565543. The next prime is 138565577. The reversal of 138565553 is 355565831.

It is a happy number.

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: 355565831 = 1033 ⋅344207.

It is a cyclic number.

It is not a de Polignac number, because 138565553 - 2⁶ = 138565489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138565553.

It is not an unprimeable number, because it can be changed into a prime (138565523) 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, 9897533 + ... + 9897546.

It is an arithmetic number, because the mean of its divisors is an integer number (39590160).

Almost surely, 2^138565553 is an apocalyptic number.

It is an amenable number.

138565553 is a deficient number, since it is larger than the sum of its proper divisors (19795087).

138565553 is an equidigital number, since it uses as much as digits as its factorization.

138565553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19795086.

The product of its digits is 270000, while the sum is 41.

The square root of 138565553 is about 11771.3870465634. The cubic root of 138565553 is about 517.4699001529.

The spelling of 138565553 in words is "one hundred thirty-eight million, five hundred sixty-five thousand, five hundred fifty-three".