16201989 has 6 divisors (see below), whose sum is σ = 23402886. Its totient is φ = 10801320.

The previous prime is 16201973. The next prime is 16202009. The reversal of 16201989 is 98910261.

It can be written as a sum of positive squares in only one way, i.e., 14861025 + 1340964 = 3855^2 + 1158^2 .

It is not a de Polignac number, because 16201989 - 2⁴ = 16201973 is a prime.

It is a super-2 number, since 2×16201989² = 525008895112242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16201909) 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 5 ways as a sum of consecutive naturals, for example, 900102 + ... + 900119.

It is an arithmetic number, because the mean of its divisors is an integer number (3900481).

Almost surely, 2^16201989 is an apocalyptic number.

It is an amenable number.

16201989 is a deficient number, since it is larger than the sum of its proper divisors (7200897).

16201989 is a wasteful number, since it uses less digits than its factorization.

16201989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800227 (or 1800224 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 16201989 is about 4025.1694374274. The cubic root of 16201989 is about 253.0401546456.

The spelling of 16201989 in words is "sixteen million, two hundred one thousand, nine hundred eighty-nine".