21623523551011 has 4 divisors (see below), whose sum is σ = 21623568808072. Its totient is φ = 21623478293952.

The previous prime is 21623523550991. The next prime is 21623523551017. The reversal of 21623523551011 is 11015532532612.

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 21623523551011 - 2¹⁵ = 21623523518243 is a prime.

It is a super-2 number, since 2×21623523551011² (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 (21623523551017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21904110 + ... + 22870003.

It is an arithmetic number, because the mean of its divisors is an integer number (5405892202018).

Almost surely, 2^{21623523551011} is an apocalyptic number.

21623523551011 is a deficient number, since it is larger than the sum of its proper divisors (45257061).

21623523551011 is an equidigital number, since it uses as much as digits as its factorization.

21623523551011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45257060.

The product of its (nonzero) digits is 54000, while the sum is 37.

The spelling of 21623523551011 in words is "twenty-one trillion, six hundred twenty-three billion, five hundred twenty-three million, five hundred fifty-one thousand, eleven".