21031443015 has 32 divisors (see below), whose sum is σ = 36718327296. Its totient is φ = 10194591360.

The previous prime is 21031443011. The next prime is 21031443049. The reversal of 21031443015 is 51034413012.

It is a happy number.

It is not a de Polignac number, because 21031443015 - 2² = 21031443011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031443011) 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 31 ways as a sum of consecutive naturals, for example, 795997 + ... + 821993.

It is an arithmetic number, because the mean of its divisors is an integer number (1147447728).

Almost surely, 2^21031443015 is an apocalyptic number.

21031443015 is a deficient number, since it is larger than the sum of its proper divisors (15686884281).

21031443015 is a wasteful number, since it uses less digits than its factorization.

21031443015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30919.

The product of its (nonzero) digits is 1440, while the sum is 24.

Adding to 21031443015 its reverse (51034413012), we get a palindrome (72065856027).

The spelling of 21031443015 in words is "twenty-one billion, thirty-one million, four hundred forty-three thousand, fifteen".