21153142021145 has 4 divisors (see below), whose sum is σ = 25383770425380. Its totient is φ = 16922513616912.

The previous prime is 21153142021133. The next prime is 21153142021157. The reversal of 21153142021145 is 54112024135112.

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

It is an interprime number because it is at equal distance from previous prime (21153142021133) and next prime (21153142021157).

It can be written as a sum of positive squares in 2 ways, for example, as 16143190943881 + 5009951077264 = 4017859^2 + 2238292^2 .

It is a cyclic number.

It is not a de Polignac number, because 21153142021145 - 2³⁴ = 21135962151961 is a prime.

It is a super-2 number, since 2×21153142021145² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

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, 2115314202110 + ... + 2115314202119.

It is an arithmetic number, because the mean of its divisors is an integer number (6345942606345).

Almost surely, 2^{21153142021145} is an apocalyptic number.

It is an amenable number.

21153142021145 is a deficient number, since it is larger than the sum of its proper divisors (4230628404235).

21153142021145 is an equidigital number, since it uses as much as digits as its factorization.

21153142021145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4230628404234.

The product of its (nonzero) digits is 9600, while the sum is 32.

Adding to 21153142021145 its reverse (54112024135112), we get a palindrome (75265166156257).

The spelling of 21153142021145 in words is "twenty-one trillion, one hundred fifty-three billion, one hundred forty-two million, twenty-one thousand, one hundred forty-five".