21252040891 has 8 divisors (see below), whose sum is σ = 21378802320. Its totient is φ = 21125324832.

The previous prime is 21252040879. The next prime is 21252040907. The reversal of 21252040891 is 19804025212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21252040891 - 2⁷ = 21252040763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21252040841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1601080 + ... + 1614298.

It is an arithmetic number, because the mean of its divisors is an integer number (2672350290).

Almost surely, 2^21252040891 is an apocalyptic number.

21252040891 is a deficient number, since it is larger than the sum of its proper divisors (126761429).

21252040891 is a wasteful number, since it uses less digits than its factorization.

21252040891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22685.

The product of its (nonzero) digits is 11520, while the sum is 34.

The spelling of 21252040891 in words is "twenty-one billion, two hundred fifty-two million, forty thousand, eight hundred ninety-one".