16139991 has 8 divisors (see below), whose sum is σ = 24594304. Its totient is φ = 9222840.

The previous prime is 16139989. The next prime is 16139993. The reversal of 16139991 is 19993161.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (16139989) and next prime (16139993).

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

It is not a de Polignac number, because 16139991 - 2¹ = 16139989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16139993) 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, 384265 + ... + 384306.

It is an arithmetic number, because the mean of its divisors is an integer number (3074288).

Almost surely, 2^16139991 is an apocalyptic number.

16139991 is a deficient number, since it is larger than the sum of its proper divisors (8454313).

16139991 is an equidigital number, since it uses as much as digits as its factorization.

16139991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768581.

The product of its digits is 13122, while the sum is 39.

The square root of 16139991 is about 4017.4607652098. The cubic root of 16139991 is about 252.7169836956.

The spelling of 16139991 in words is "sixteen million, one hundred thirty-nine thousand, nine hundred ninety-one".