21152261023 has 4 divisors (see below), whose sum is σ = 21169992528. Its totient is φ = 21134529520.

The previous prime is 21152261017. The next prime is 21152261057. The reversal of 21152261023 is 32016225112.

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 21152261023 - 2¹³ = 21152252831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152261323) 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, 8863963 + ... + 8866348.

It is an arithmetic number, because the mean of its divisors is an integer number (5292498132).

Almost surely, 2^21152261023 is an apocalyptic number.

21152261023 is a deficient number, since it is larger than the sum of its proper divisors (17731505).

21152261023 is a wasteful number, since it uses less digits than its factorization.

21152261023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17731504.

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 21152261023 its reverse (32016225112), we get a palindrome (53168486135).

The spelling of 21152261023 in words is "twenty-one billion, one hundred fifty-two million, two hundred sixty-one thousand, twenty-three".