15136421 has 4 divisors (see below), whose sum is σ = 15505644. Its totient is φ = 14767200.

The previous prime is 15136417. The next prime is 15136423. The reversal of 15136421 is 12463151.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 923521 + 14212900 = 961^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 15136421 - 2² = 15136417 is a prime.

It is a super-2 number, since 2×15136421² = 458222481378482, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15136423) 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, 184550 + ... + 184631.

It is an arithmetic number, because the mean of its divisors is an integer number (3876411).

Almost surely, 2^15136421 is an apocalyptic number.

It is an amenable number.

15136421 is a deficient number, since it is larger than the sum of its proper divisors (369223).

15136421 is an equidigital number, since it uses as much as digits as its factorization.

15136421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369222.

The product of its digits is 720, while the sum is 23.

The square root of 15136421 is about 3890.5553588145. Note that the first 3 decimals coincide. The cubic root of 15136421 is about 247.3666036249.

Adding to 15136421 its reverse (12463151), we get a palindrome (27599572).

The spelling of 15136421 in words is "fifteen million, one hundred thirty-six thousand, four hundred twenty-one".