21612065043 has 16 divisors (see below), whose sum is σ = 29069531136. Its totient is φ = 14281856160.

The previous prime is 21612065029. The next prime is 21612065063. The reversal of 21612065043 is 34056021612.

It is not a de Polignac number, because 21612065043 - 2⁵ = 21612065011 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21612065043.

It is not an unprimeable number, because it can be changed into a prime (21612065063) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95521 + ... + 228797.

It is an arithmetic number, because the mean of its divisors is an integer number (1816845696).

Almost surely, 2^21612065043 is an apocalyptic number.

21612065043 is a deficient number, since it is larger than the sum of its proper divisors (7457466093).

21612065043 is a wasteful number, since it uses less digits than its factorization.

21612065043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133754.

The product of its (nonzero) digits is 8640, while the sum is 30.

Adding to 21612065043 its reverse (34056021612), we get a palindrome (55668086655).

The spelling of 21612065043 in words is "twenty-one billion, six hundred twelve million, sixty-five thousand, forty-three".