16253981 has 8 divisors (see below), whose sum is σ = 16543800. Its totient is φ = 15966720.

The previous prime is 16253933. The next prime is 16253983. The reversal of 16253981 is 18935261.

It can be written as a sum of positive squares in 4 ways, for example, as 722500 + 15531481 = 850^2 + 3941^2 .

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 16253981 - 2¹⁴ = 16237597 is a prime.

It is a super-2 number, since 2×16253981² = 528383796696722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16253983) 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, 15605 + ... + 16613.

It is an arithmetic number, because the mean of its divisors is an integer number (2067975).

Almost surely, 2^16253981 is an apocalyptic number.

It is an amenable number.

16253981 is a deficient number, since it is larger than the sum of its proper divisors (289819).

16253981 is a wasteful number, since it uses less digits than its factorization.

16253981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1279.

The product of its digits is 12960, while the sum is 35.

The square root of 16253981 is about 4031.6226261891. The cubic root of 16253981 is about 253.3105333051.

The spelling of 16253981 in words is "sixteen million, two hundred fifty-three thousand, nine hundred eighty-one".