15340021 has 4 divisors (see below), whose sum is σ = 15406092. Its totient is φ = 15273952.

The previous prime is 15340007. The next prime is 15340033. The reversal of 15340021 is 12004351.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12004351 = 137 ⋅87623.

It can be written as a sum of positive squares in 2 ways, for example, as 2480625 + 12859396 = 1575^2 + 3586^2 .

It is a cyclic number.

It is not a de Polignac number, because 15340021 - 2¹⁹ = 14815733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15339977 and 15340004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15340081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32686 + ... + 33151.

It is an arithmetic number, because the mean of its divisors is an integer number (3851523).

Almost surely, 2^15340021 is an apocalyptic number.

It is an amenable number.

15340021 is a deficient number, since it is larger than the sum of its proper divisors (66071).

15340021 is an equidigital number, since it uses as much as digits as its factorization.

15340021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66070.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 15340021 is about 3916.6338863876. The cubic root of 15340021 is about 248.4707769805.

Adding to 15340021 its reverse (12004351), we get a palindrome (27344372).

The spelling of 15340021 in words is "fifteen million, three hundred forty thousand, twenty-one".