138720550 has 12 divisors (see below), whose sum is σ = 258020316. Its totient is φ = 55488200.

The previous prime is 138720541. The next prime is 138720551. The reversal of 138720550 is 55027831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138720551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1387156 + ... + 1387255.

It is an arithmetic number, because the mean of its divisors is an integer number (21501693).

Almost surely, 2^138720550 is an apocalyptic number.

138720550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138720550 is a deficient number, since it is larger than the sum of its proper divisors (119299766).

138720550 is a wasteful number, since it uses less digits than its factorization.

138720550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2774423 (or 2774418 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 138720550 is about 11777.9688401693. The cubic root of 138720550 is about 517.6627725111.

The spelling of 138720550 in words is "one hundred thirty-eight million, seven hundred twenty thousand, five hundred fifty".