21124043545 has 32 divisors (see below), whose sum is σ = 28344577536. Its totient is φ = 14981280000.

The previous prime is 21124043533. The next prime is 21124043557. The reversal of 21124043545 is 54534042112.

It is an interprime number because it is at equal distance from previous prime (21124043533) and next prime (21124043557).

It is not a de Polignac number, because 21124043545 - 2⁵ = 21124043513 is a prime.

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, 701295 + ... + 730795.

It is an arithmetic number, because the mean of its divisors is an integer number (885768048).

Almost surely, 2^21124043545 is an apocalyptic number.

It is an amenable number.

21124043545 is a deficient number, since it is larger than the sum of its proper divisors (7220533991).

21124043545 is a wasteful number, since it uses less digits than its factorization.

21124043545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29841.

The product of its (nonzero) digits is 19200, while the sum is 31.

Adding to 21124043545 its reverse (54534042112), we get a palindrome (75658085657).

The spelling of 21124043545 in words is "twenty-one billion, one hundred twenty-four million, forty-three thousand, five hundred forty-five".