21002142323 has 4 divisors (see below), whose sum is σ = 21006567648. Its totient is φ = 20997717000.

The previous prime is 21002142263. The next prime is 21002142401. The reversal of 21002142323 is 32324120012.

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 21002142323 - 2¹⁴ = 21002125939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002142295 and 21002142304.

It is not an unprimeable number, because it can be changed into a prime (21002442323) 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, 2205536 + ... + 2215037.

It is an arithmetic number, because the mean of its divisors is an integer number (5251641912).

Almost surely, 2^21002142323 is an apocalyptic number.

21002142323 is a deficient number, since it is larger than the sum of its proper divisors (4425325).

21002142323 is an equidigital number, since it uses as much as digits as its factorization.

21002142323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4425324.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21002142323 its reverse (32324120012), we get a palindrome (53326262335).

The spelling of 21002142323 in words is "twenty-one billion, two million, one hundred forty-two thousand, three hundred twenty-three".