16129991 has 8 divisors (see below), whose sum is σ = 17186544. Its totient is φ = 15085440.

The previous prime is 16129963. The next prime is 16130021. The reversal of 16129991 is 19992161.

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 16129991 - 2¹⁴ = 16113607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16129901) 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, 140 + ... + 5681.

It is an arithmetic number, because the mean of its divisors is an integer number (2148318).

Almost surely, 2^16129991 is an apocalyptic number.

16129991 is a deficient number, since it is larger than the sum of its proper divisors (1056553).

16129991 is a wasteful number, since it uses less digits than its factorization.

16129991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6001.

The product of its digits is 8748, while the sum is 38.

The square root of 16129991 is about 4016.2160051471. The cubic root of 16129991 is about 252.6647801980.

The spelling of 16129991 in words is "sixteen million, one hundred twenty-nine thousand, nine hundred ninety-one".