21545543043245 has 32 divisors (see below), whose sum is σ = 27896075730432. Its totient is φ = 15880514867712.

The previous prime is 21545543043239. The next prime is 21545543043251. The reversal of 21545543043245 is 54234034554512.

It is an interprime number because it is at equal distance from previous prime (21545543043239) and next prime (21545543043251).

It is a cyclic number.

It is not a de Polignac number, because 21545543043245 - 2⁴ = 21545543043229 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21545543043245.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 105691457 + ... + 105895113.

It is an arithmetic number, because the mean of its divisors is an integer number (871752366576).

Almost surely, 2^{21545543043245} is an apocalyptic number.

It is an amenable number.

21545543043245 is a deficient number, since it is larger than the sum of its proper divisors (6350532687187).

21545543043245 is a wasteful number, since it uses less digits than its factorization.

21545543043245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206741.

The product of its (nonzero) digits is 5760000, while the sum is 47.

Adding to 21545543043245 its reverse (54234034554512), we get a palindrome (75779577597757).

The spelling of 21545543043245 in words is "twenty-one trillion, five hundred forty-five billion, five hundred forty-three million, forty-three thousand, two hundred forty-five".