138723784 has 8 divisors (see below), whose sum is σ = 260107110. Its totient is φ = 69361888.

The previous prime is 138723779. The next prime is 138723797. The reversal of 138723784 is 487327831.

It can be written as a sum of positive squares in only one way, i.e., 138721284 + 2500 = 11778^2 + 50^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 138723784.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8670229 + ... + 8670244.

Almost surely, 2^138723784 is an apocalyptic number.

It is an amenable number.

138723784 is a deficient number, since it is larger than the sum of its proper divisors (121383326).

138723784 is a wasteful number, since it uses less digits than its factorization.

138723784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17340479 (or 17340475 counting only the distinct ones).

The product of its digits is 225792, while the sum is 43.

The square root of 138723784 is about 11778.1061295949. The cubic root of 138723784 is about 517.6667952469. Note that the first 3 decimals are identical.

The spelling of 138723784 in words is "one hundred thirty-eight million, seven hundred twenty-three thousand, seven hundred eighty-four".