21612405045 has 32 divisors (see below), whose sum is σ = 43112540160. Its totient is φ = 8981778240.

The previous prime is 21612405043. The next prime is 21612405077. The reversal of 21612405045 is 54050421612.

It is not a de Polignac number, because 21612405045 - 2¹ = 21612405043 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612405043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9354865 + ... + 9357174.

It is an arithmetic number, because the mean of its divisors is an integer number (1347266880).

Almost surely, 2^21612405045 is an apocalyptic number.

It is an amenable number.

21612405045 is a deficient number, since it is larger than the sum of its proper divisors (21500135115).

21612405045 is a wasteful number, since it uses less digits than its factorization.

21612405045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18712065.

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 21612405045 its reverse (54050421612), we get a palindrome (75662826657).

The spelling of 21612405045 in words is "twenty-one billion, six hundred twelve million, four hundred five thousand, forty-five".