138121473 has 16 divisors (see below), whose sum is σ = 211767296. Its totient is φ = 78440400.

The previous prime is 138121457. The next prime is 138121541. The reversal of 138121473 is 374121831.

It is not a de Polignac number, because 138121473 - 2⁴ = 138121457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 138121473.

It is not an unprimeable number, because it can be changed into a prime (138121453) 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, 16753 + ... + 23598.

It is an arithmetic number, because the mean of its divisors is an integer number (13235456).

Almost surely, 2^138121473 is an apocalyptic number.

It is an amenable number.

138121473 is a deficient number, since it is larger than the sum of its proper divisors (73645823).

138121473 is a wasteful number, since it uses less digits than its factorization.

138121473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40524.

The product of its digits is 4032, while the sum is 30.

The square root of 138121473 is about 11752.5092214386. The cubic root of 138121473 is about 516.9165063387.

The spelling of 138121473 in words is "one hundred thirty-eight million, one hundred twenty-one thousand, four hundred seventy-three".