21243928027 has 4 divisors (see below), whose sum is σ = 24278774896. Its totient is φ = 18209081160.

The previous prime is 21243927997. The next prime is 21243928091. The reversal of 21243928027 is 72082934212.

It is a happy number.

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 21243928027 - 2²³ = 21235539419 is a prime.

It is a super-2 number, since 2×21243928027² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21243928327) 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, 1517423424 + ... + 1517423437.

It is an arithmetic number, because the mean of its divisors is an integer number (6069693724).

Almost surely, 2^21243928027 is an apocalyptic number.

21243928027 is a deficient number, since it is larger than the sum of its proper divisors (3034846869).

21243928027 is an equidigital number, since it uses as much as digits as its factorization.

21243928027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3034846868.

The product of its (nonzero) digits is 96768, while the sum is 40.

The spelling of 21243928027 in words is "twenty-one billion, two hundred forty-three million, nine hundred twenty-eight thousand, twenty-seven".