13642021 has 4 divisors (see below), whose sum is σ = 13828972. Its totient is φ = 13455072.

The previous prime is 13642003. The next prime is 13642033. The reversal of 13642021 is 12024631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12024631 = 71 ⋅169361.

It can be written as a sum of positive squares in 2 ways, for example, as 8328996 + 5313025 = 2886^2 + 2305^2 .

It is a cyclic number.

It is not a de Polignac number, because 13642021 - 2⁵ = 13641989 is a prime.

It is a super-2 number, since 2×13642021² = 372209473928882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13642021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13642001) 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, 93366 + ... + 93511.

It is an arithmetic number, because the mean of its divisors is an integer number (3457243).

Almost surely, 2^13642021 is an apocalyptic number.

It is an amenable number.

13642021 is a deficient number, since it is larger than the sum of its proper divisors (186951).

13642021 is an equidigital number, since it uses as much as digits as its factorization.

13642021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186950.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 13642021 is about 3693.5106606046. The cubic root of 13642021 is about 238.9422256084.

Adding to 13642021 its reverse (12024631), we get a palindrome (25666652).

The spelling of 13642021 in words is "thirteen million, six hundred forty-two thousand, twenty-one".