21402123013 has 8 divisors (see below), whose sum is σ = 23052471200. Its totient is φ = 19804166928.

The previous prime is 21402123011. The next prime is 21402123019. The reversal of 21402123013 is 31032120412.

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 not a de Polignac number, because 21402123013 - 2¹ = 21402123011 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402123011) 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, 13097178 + ... + 13098811.

It is an arithmetic number, because the mean of its divisors is an integer number (2881558900).

Almost surely, 2^21402123013 is an apocalyptic number.

It is an amenable number.

21402123013 is a deficient number, since it is larger than the sum of its proper divisors (1650348187).

21402123013 is a wasteful number, since it uses less digits than its factorization.

21402123013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26196051.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21402123013 its reverse (31032120412), we get a palindrome (52434243425).

The spelling of 21402123013 in words is "twenty-one billion, four hundred two million, one hundred twenty-three thousand, thirteen".