21240431315 has 8 divisors (see below), whose sum is σ = 25969433328. Its totient is φ = 16671734560.

The previous prime is 21240431281. The next prime is 21240431323. The reversal of 21240431315 is 51313404212.

It is a happy number.

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

It is not a de Polignac number, because 21240431315 - 2¹⁶ = 21240365779 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40076021 + ... + 40076550.

It is an arithmetic number, because the mean of its divisors is an integer number (3246179166).

Almost surely, 2^21240431315 is an apocalyptic number.

21240431315 is a deficient number, since it is larger than the sum of its proper divisors (4729002013).

21240431315 is an equidigital number, since it uses as much as digits as its factorization.

21240431315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80152629.

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 21240431315 its reverse (51313404212), we get a palindrome (72553835527).

The spelling of 21240431315 in words is "twenty-one billion, two hundred forty million, four hundred thirty-one thousand, three hundred fifteen".