138402993 has 16 divisors (see below), whose sum is σ = 191923200. Its totient is φ = 88609920.

The previous prime is 138402989. The next prime is 138403009. The reversal of 138402993 is 399204831.

It is not a de Polignac number, because 138402993 - 2² = 138402989 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138402923) 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, 12453 + ... + 20781.

It is an arithmetic number, because the mean of its divisors is an integer number (11995200).

Almost surely, 2^138402993 is an apocalyptic number.

It is an amenable number.

138402993 is a deficient number, since it is larger than the sum of its proper divisors (53520207).

138402993 is a wasteful number, since it uses less digits than its factorization.

138402993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8552.

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 138402993 is about 11764.4801415107. The cubic root of 138402993 is about 517.2674620960.

The spelling of 138402993 in words is "one hundred thirty-eight million, four hundred two thousand, nine hundred ninety-three".