16721131 has 8 divisors (see below), whose sum is σ = 19434240. Its totient is φ = 14089128.

The previous prime is 16721119. The next prime is 16721141. The reversal of 16721131 is 13112761.

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 16721131 - 2⁹ = 16720619 is a prime.

It is a super-2 number, since 2×16721131² = 559192443838322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16721141) 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, 19831 + ... + 20656.

It is an arithmetic number, because the mean of its divisors is an integer number (2429280).

Almost surely, 2^16721131 is an apocalyptic number.

16721131 is a deficient number, since it is larger than the sum of its proper divisors (2713109).

16721131 is an equidigital number, since it uses as much as digits as its factorization.

16721131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40553.

The product of its digits is 252, while the sum is 22.

The square root of 16721131 is about 4089.1479552591. The cubic root of 16721131 is about 255.7144184757.

Adding to 16721131 its reverse (13112761), we get a palindrome (29833892).

The spelling of 16721131 in words is "sixteen million, seven hundred twenty-one thousand, one hundred thirty-one".