16139281 has 6 divisors (see below), whose sum is σ = 16544246. Its totient is φ = 15744000.

The previous prime is 16139269. The next prime is 16139293. The reversal of 16139281 is 18293161.

It is an interprime number because it is at equal distance from previous prime (16139269) and next prime (16139293).

It can be written as a sum of positive squares in 3 ways, for example, as 11025 + 16128256 = 105^2 + 4016^2 .

It is not a de Polignac number, because 16139281 - 2⁷ = 16139153 is a prime.

It is a super-2 number, since 2×16139281² = 520952782393922, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16139581) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3120 + ... + 6481.

Almost surely, 2^16139281 is an apocalyptic number.

It is an amenable number.

16139281 is a deficient number, since it is larger than the sum of its proper divisors (404965).

16139281 is an frugal number, since it uses more digits than its factorization.

16139281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9683 (or 9642 counting only the distinct ones).

The product of its digits is 2592, while the sum is 31.

The square root of 16139281 is about 4017.3723999649. The cubic root of 16139281 is about 252.7132779585.

The spelling of 16139281 in words is "sixteen million, one hundred thirty-nine thousand, two hundred eighty-one".