138565780 has 24 divisors (see below), whose sum is σ = 297757152. Its totient is φ = 54136992.

The previous prime is 138565769. The next prime is 138565781. The reversal of 138565780 is 87565831.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138565781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79702 + ... + 81421.

It is an arithmetic number, because the mean of its divisors is an integer number (12406548).

Almost surely, 2^138565780 is an apocalyptic number.

138565780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138565780 is an abundant number, since it is smaller than the sum of its proper divisors (159191372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138565780 is a wasteful number, since it uses less digits than its factorization.

138565780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161175 (or 161173 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 43.

The square root of 138565780 is about 11771.3966885837. The cubic root of 138565780 is about 517.4701827282.

The spelling of 138565780 in words is "one hundred thirty-eight million, five hundred sixty-five thousand, seven hundred eighty".