16402989 has 4 divisors (see below), whose sum is σ = 21870656. Its totient is φ = 10935324.

The previous prime is 16402949. The next prime is 16403017. The reversal of 16402989 is 98920461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98920461 = 3 ⋅32973487.

It is not a de Polignac number, because 16402989 - 2⁷ = 16402861 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 (16402949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2733829 + ... + 2733834.

It is an arithmetic number, because the mean of its divisors is an integer number (5467664).

Almost surely, 2^16402989 is an apocalyptic number.

It is an amenable number.

16402989 is a deficient number, since it is larger than the sum of its proper divisors (5467667).

16402989 is an equidigital number, since it uses as much as digits as its factorization.

16402989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5467666.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 16402989 is about 4050.0603699204. The cubic root of 16402989 is about 254.0822526925.

It can be divided in two parts, 16402 and 989, that added together give a triangular number (17391 = T₁₈₆).

The spelling of 16402989 in words is "sixteen million, four hundred two thousand, nine hundred eighty-nine".