138565784 has 64 divisors (see below), whose sum is σ = 322713600. Its totient is φ = 54432000.

The previous prime is 138565781. The next prime is 138565787. The reversal of 138565784 is 487565831.

It is an interprime number because it is at equal distance from previous prime (138565781) and next prime (138565787).

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 15 ways as a sum of consecutive naturals, for example, 30884 + ... + 35084.

It is an arithmetic number, because the mean of its divisors is an integer number (5042400).

Almost surely, 2^138565784 is an apocalyptic number.

138565784 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138565784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161356800).

138565784 is an abundant number, since it is smaller than the sum of its proper divisors (184147816).

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

138565784 is a wasteful number, since it uses less digits than its factorization.

138565784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4264 (or 4260 counting only the distinct ones).

The product of its digits is 806400, while the sum is 47.

The square root of 138565784 is about 11771.3968584871. The cubic root of 138565784 is about 517.4701877075.

Adding to 138565784 its sum of digits (47), we get a palindrome (138565831).

The spelling of 138565784 in words is "one hundred thirty-eight million, five hundred sixty-five thousand, seven hundred eighty-four".