21151315042433 has 4 divisors (see below), whose sum is σ = 21722972205780. Its totient is φ = 20579657879088.

The previous prime is 21151315042423. The next prime is 21151315042439. The reversal of 21151315042433 is 33424051315112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20174048351809 + 977266690624 = 4491553^2 + 988568^2 .

It is a cyclic number.

It is not a de Polignac number, because 21151315042433 - 2³⁶ = 21082595565697 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21151315042393 and 21151315042402.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 285828581618 + ... + 285828581691.

It is an arithmetic number, because the mean of its divisors is an integer number (5430743051445).

Almost surely, 2^{21151315042433} is an apocalyptic number.

It is an amenable number.

21151315042433 is a deficient number, since it is larger than the sum of its proper divisors (571657163347).

21151315042433 is an equidigital number, since it uses as much as digits as its factorization.

21151315042433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571657163346.

The product of its (nonzero) digits is 43200, while the sum is 35.

Adding to 21151315042433 its reverse (33424051315112), we get a palindrome (54575366357545).

The spelling of 21151315042433 in words is "twenty-one trillion, one hundred fifty-one billion, three hundred fifteen million, forty-two thousand, four hundred thirty-three".