21015315131 has 8 divisors (see below), whose sum is σ = 21762399600. Its totient is φ = 20269725280.

The previous prime is 21015315109. The next prime is 21015315151. The reversal of 21015315131 is 13151351012.

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

It is a cyclic number.

It is not a de Polignac number, because 21015315131 - 2¹⁴ = 21015298747 is a prime.

It is a super-2 number, since 2×21015315131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21015315097 and 21015315106.

It is not an unprimeable number, because it can be changed into a prime (21015315151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344996 + ... + 401313.

It is an arithmetic number, because the mean of its divisors is an integer number (2720299950).

Almost surely, 2^21015315131 is an apocalyptic number.

21015315131 is a deficient number, since it is larger than the sum of its proper divisors (747084469).

21015315131 is an equidigital number, since it uses as much as digits as its factorization.

21015315131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747309.

The product of its (nonzero) digits is 450, while the sum is 23.

Adding to 21015315131 its reverse (13151351012), we get a palindrome (34166666143).

The spelling of 21015315131 in words is "twenty-one billion, fifteen million, three hundred fifteen thousand, one hundred thirty-one".