21420014243 has 6 divisors (see below), whose sum is σ = 21622083756. Its totient is φ = 21219815852.

The previous prime is 21420014227. The next prime is 21420014299. The reversal of 21420014243 is 34241002412.

It is not a de Polignac number, because 21420014243 - 2⁴ = 21420014227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21420010243) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 924005 + ... + 946902.

It is an arithmetic number, because the mean of its divisors is an integer number (3603680626).

Almost surely, 2^21420014243 is an apocalyptic number.

21420014243 is a deficient number, since it is larger than the sum of its proper divisors (202069513).

21420014243 is an equidigital number, since it uses as much as digits as its factorization.

21420014243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1871121 (or 1871014 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21420014243 its reverse (34241002412), we get a palindrome (55661016655).

The spelling of 21420014243 in words is "twenty-one billion, four hundred twenty million, fourteen thousand, two hundred forty-three".