16121539 has 12 divisors (see below), whose sum is σ = 19014744. Its totient is φ = 13626144.

The previous prime is 16121537. The next prime is 16121561. The reversal of 16121539 is 93512161.

It is not a de Polignac number, because 16121539 - 2¹ = 16121537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16121531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1324 + ... + 5830.

It is an arithmetic number, because the mean of its divisors is an integer number (1584562).

Almost surely, 2^16121539 is an apocalyptic number.

16121539 is a deficient number, since it is larger than the sum of its proper divisors (2893205).

16121539 is an equidigital number, since it uses as much as digits as its factorization.

16121539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4594 (or 4587 counting only the distinct ones).

The product of its digits is 1620, while the sum is 28.

The square root of 16121539 is about 4015.1636330292. The cubic root of 16121539 is about 252.6206409746.

The spelling of 16121539 in words is "sixteen million, one hundred twenty-one thousand, five hundred thirty-nine".