21345013423 has 8 divisors (see below), whose sum is σ = 21854031056. Its totient is φ = 20836569600.

The previous prime is 21345013381. The next prime is 21345013447. The reversal of 21345013423 is 32431054312.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21345013423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21345013391 and 21345013400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21345013223) 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, 67698 + ... + 217423.

It is an arithmetic number, because the mean of its divisors is an integer number (2731753882).

Almost surely, 2^21345013423 is an apocalyptic number.

21345013423 is a deficient number, since it is larger than the sum of its proper divisors (509017633).

21345013423 is a wasteful number, since it uses less digits than its factorization.

21345013423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286905.

The product of its (nonzero) digits is 8640, while the sum is 28.

Adding to 21345013423 its reverse (32431054312), we get a palindrome (53776067735).

The spelling of 21345013423 in words is "twenty-one billion, three hundred forty-five million, thirteen thousand, four hundred twenty-three".