21601625053123 has 4 divisors (see below), whose sum is σ = 22009202884368. Its totient is φ = 21194047221880.

The previous prime is 21601625053103. The next prime is 21601625053133. The reversal of 21601625053123 is 32135052610612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21601625053123 - 2⁵ = 21601625053091 is a prime.

It is a super-2 number, since 2×21601625053123² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21601625053103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203788915543 + ... + 203788915648.

It is an arithmetic number, because the mean of its divisors is an integer number (5502300721092).

Almost surely, 2^{21601625053123} is an apocalyptic number.

21601625053123 is a deficient number, since it is larger than the sum of its proper divisors (407577831245).

21601625053123 is an equidigital number, since it uses as much as digits as its factorization.

21601625053123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407577831244.

The product of its (nonzero) digits is 64800, while the sum is 37.

Adding to 21601625053123 its reverse (32135052610612), we get a palindrome (53736677663735).

The spelling of 21601625053123 in words is "twenty-one trillion, six hundred one billion, six hundred twenty-five million, fifty-three thousand, one hundred twenty-three".