21040553433145 has 4 divisors (see below), whose sum is σ = 25248664119780. Its totient is φ = 16832442746512.

The previous prime is 21040553433103. The next prime is 21040553433191. The reversal of 21040553433145 is 54133435504012.

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 11820421591056 + 9220131842089 = 3438084^2 + 3036467^2 .

It is a cyclic number.

It is not a de Polignac number, because 21040553433145 - 2⁷ = 21040553433017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21040553433098 and 21040553433107.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2104055343310 + ... + 2104055343319.

It is an arithmetic number, because the mean of its divisors is an integer number (6312166029945).

Almost surely, 2^{21040553433145} is an apocalyptic number.

It is an amenable number.

21040553433145 is a deficient number, since it is larger than the sum of its proper divisors (4208110686635).

21040553433145 is an equidigital number, since it uses as much as digits as its factorization.

21040553433145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208110686634.

The product of its (nonzero) digits is 432000, while the sum is 40.

Adding to 21040553433145 its reverse (54133435504012), we get a palindrome (75173988937157).

The spelling of 21040553433145 in words is "twenty-one trillion, forty billion, five hundred fifty-three million, four hundred thirty-three thousand, one hundred forty-five".