21504131243403 has 8 divisors (see below), whose sum is σ = 29597083862016. Its totient is φ = 13873633060200.

The previous prime is 21504131243383. The next prime is 21504131243423. The reversal of 21504131243403 is 30434213140512.

It is an interprime number because it is at equal distance from previous prime (21504131243383) and next prime (21504131243423).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21504131243403 - 2¹² = 21504131239307 is a prime.

It is a super-3 number, since 3×21504131243403³ (a number of 41 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21504131243423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115613608743 + ... + 115613608928.

It is an arithmetic number, because the mean of its divisors is an integer number (3699635482752).

Almost surely, 2^{21504131243403} is an apocalyptic number.

21504131243403 is a deficient number, since it is larger than the sum of its proper divisors (8092952618613).

21504131243403 is a wasteful number, since it uses less digits than its factorization.

21504131243403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231227217705.

The product of its (nonzero) digits is 34560, while the sum is 33.

Adding to 21504131243403 its reverse (30434213140512), we get a palindrome (51938344383915).

The spelling of 21504131243403 in words is "twenty-one trillion, five hundred four billion, one hundred thirty-one million, two hundred forty-three thousand, four hundred three".