21607435216123 has 2 divisors, whose sum is σ = 21607435216124. Its totient is φ = 21607435216122.

The previous prime is 21607435216111. The next prime is 21607435216153. The reversal of 21607435216123 is 32161253470612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21607435216123 is a prime.

It is a super-2 number, since 2×21607435216123² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21607435216123.

It is not a weakly prime, because it can be changed into another prime (21607435216153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10803717608061 + 10803717608062.

It is an arithmetic number, because the mean of its divisors is an integer number (10803717608062).

Almost surely, 2^{21607435216123} is an apocalyptic number.

21607435216123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21607435216123 is an equidigital number, since it uses as much as digits as its factorization.

21607435216123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 43.

Adding to 21607435216123 its reverse (32161253470612), we get a palindrome (53768688686735).

The spelling of 21607435216123 in words is "twenty-one trillion, six hundred seven billion, four hundred thirty-five million, two hundred sixteen thousand, one hundred twenty-three".