21420423343 has 8 divisors (see below), whose sum is σ = 23808635856. Its totient is φ = 19105694400.

The previous prime is 21420423331. The next prime is 21420423373. The reversal of 21420423343 is 34332402412.

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

It is not a de Polignac number, because 21420423343 - 2²¹ = 21418326191 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 (21420423373) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18370278 + ... + 18371443.

It is an arithmetic number, because the mean of its divisors is an integer number (2976079482).

Almost surely, 2^21420423343 is an apocalyptic number.

21420423343 is a deficient number, since it is larger than the sum of its proper divisors (2388212513).

21420423343 is a wasteful number, since it uses less digits than its factorization.

21420423343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36741785.

The product of its (nonzero) digits is 13824, while the sum is 28.

Adding to 21420423343 its reverse (34332402412), we get a palindrome (55752825755).

The spelling of 21420423343 in words is "twenty-one billion, four hundred twenty million, four hundred twenty-three thousand, three hundred forty-three".