21520414023 has 4 divisors (see below), whose sum is σ = 28693885368. Its totient is φ = 14346942680.

The previous prime is 21520414009. The next prime is 21520414031. The reversal of 21520414023 is 32041402512.

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 21520414023 - 2⁸ = 21520413767 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21520413984 and 21520414002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520414063) 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, 3586735668 + ... + 3586735673.

It is an arithmetic number, because the mean of its divisors is an integer number (7173471342).

Almost surely, 2^21520414023 is an apocalyptic number.

21520414023 is a deficient number, since it is larger than the sum of its proper divisors (7173471345).

21520414023 is an equidigital number, since it uses as much as digits as its factorization.

21520414023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7173471344.

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 21520414023 its reverse (32041402512), we get a palindrome (53561816535).

The spelling of 21520414023 in words is "twenty-one billion, five hundred twenty million, four hundred fourteen thousand, twenty-three".