21162527321 has 4 divisors (see below), whose sum is σ = 22790414052. Its totient is φ = 19534640592.

The previous prime is 21162527317. The next prime is 21162527327. The reversal of 21162527321 is 12372526112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7636837321 + 13525690000 = 87389^2 + 116300^2 .

It is a cyclic number.

It is not a de Polignac number, because 21162527321 - 2² = 21162527317 is a prime.

It is a super-2 number, since 2×21162527321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21162527327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 813943346 + ... + 813943371.

It is an arithmetic number, because the mean of its divisors is an integer number (5697603513).

Almost surely, 2^21162527321 is an apocalyptic number.

It is an amenable number.

21162527321 is a deficient number, since it is larger than the sum of its proper divisors (1627886731).

21162527321 is a wasteful number, since it uses less digits than its factorization.

21162527321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627886730.

The product of its digits is 10080, while the sum is 32.

The spelling of 21162527321 in words is "twenty-one billion, one hundred sixty-two million, five hundred twenty-seven thousand, three hundred twenty-one".