138684290 has 16 divisors (see below), whose sum is σ = 249766200. Its totient is φ = 55443840.

The previous prime is 138684281. The next prime is 138684311. The reversal of 138684290 is 92486831.

It can be written as a sum of positive squares in 4 ways, for example, as 29669809 + 109014481 = 5447^2 + 10441^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32480 + ... + 36500.

Almost surely, 2^138684290 is an apocalyptic number.

138684290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138684290 is a deficient number, since it is larger than the sum of its proper divisors (111081910).

138684290 is a wasteful number, since it uses less digits than its factorization.

138684290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7477.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 138684290 is about 11776.4294249148. The cubic root of 138684290 is about 517.6176648279.

The spelling of 138684290 in words is "one hundred thirty-eight million, six hundred eighty-four thousand, two hundred ninety".