21151315042432 has 32 divisors (see below), whose sum is σ = 44616055172220. Its totient is φ = 9953560018944.

The previous prime is 21151315042423. The next prime is 21151315042439. The reversal of 21151315042432 is 23424051315112.

It can be written as a sum of positive squares in 2 ways, for example, as 20313914353216 + 837400689216 = 4507096^2 + 915096^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (21151315042439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4860134553 + ... + 4860138904.

Almost surely, 2^{21151315042432} is an apocalyptic number.

It is an amenable number.

21151315042432 is an abundant number, since it is smaller than the sum of its proper divisors (23464740129788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21151315042432 is an equidigital number, since it uses as much as digits as its factorization.

21151315042432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9720273488 (or 9720273476 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 34.

Adding to 21151315042432 its reverse (23424051315112), we get a palindrome (44575366357544).

The spelling of 21151315042432 in words is "twenty-one trillion, one hundred fifty-one billion, three hundred fifteen million, forty-two thousand, four hundred thirty-two".