138991801 has 8 divisors (see below), whose sum is σ = 151792704. Its totient is φ = 126492240.

The previous prime is 138991757. The next prime is 138991837. The reversal of 138991801 is 108199831.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138991801 - 2⁷ = 138991673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138991841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74371 + ... + 76216.

It is an arithmetic number, because the mean of its divisors is an integer number (18974088).

Almost surely, 2^138991801 is an apocalyptic number.

It is an amenable number.

138991801 is a deficient number, since it is larger than the sum of its proper divisors (12800903).

138991801 is a wasteful number, since it uses less digits than its factorization.

138991801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150671.

The product of its (nonzero) digits is 15552, while the sum is 40.

The square root of 138991801 is about 11789.4784023722. The cubic root of 138991801 is about 517.9999614893. Note that the first 4 decimals are identical.

The spelling of 138991801 in words is "one hundred thirty-eight million, nine hundred ninety-one thousand, eight hundred one".