21421003423 has 8 divisors (see below), whose sum is σ = 21743172992. Its totient is φ = 21098906136.

The previous prime is 21421003411. The next prime is 21421003433. The reversal of 21421003423 is 32430012412.

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-21421003423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21421003394 and 21421003403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421003433) 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, 1039486 + ... + 1059892.

It is an arithmetic number, because the mean of its divisors is an integer number (2717896624).

Almost surely, 2^21421003423 is an apocalyptic number.

21421003423 is a deficient number, since it is larger than the sum of its proper divisors (322169569).

21421003423 is a wasteful number, since it uses less digits than its factorization.

21421003423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36141.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21421003423 its reverse (32430012412), we get a palindrome (53851015835).

The spelling of 21421003423 in words is "twenty-one billion, four hundred twenty-one million, three thousand, four hundred twenty-three".