16570121 has 4 divisors (see below), whose sum is σ = 17544852. Its totient is φ = 15595392.

The previous prime is 16570111. The next prime is 16570123. The reversal of 16570121 is 12107561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12107561 = 73 ⋅165857.

It can be written as a sum of positive squares in 2 ways, for example, as 13801225 + 2768896 = 3715^2 + 1664^2 .

It is not a de Polignac number, because 16570121 - 2¹⁴ = 16553737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16570123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 487340 + ... + 487373.

It is an arithmetic number, because the mean of its divisors is an integer number (4386213).

Almost surely, 2^16570121 is an apocalyptic number.

It is an amenable number.

16570121 is a deficient number, since it is larger than the sum of its proper divisors (974731).

16570121 is an equidigital number, since it uses as much as digits as its factorization.

16570121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974730.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 16570121 is about 4070.6413499595. The cubic root of 16570121 is about 254.9422963115.

Adding to 16570121 its reverse (12107561), we get a palindrome (28677682).

The spelling of 16570121 in words is "sixteen million, five hundred seventy thousand, one hundred twenty-one".