21343254121 has 16 divisors (see below), whose sum is σ = 25048476288. Its totient is φ = 17805110400.

The previous prime is 21343254073. The next prime is 21343254131. The reversal of 21343254121 is 12145234312.

It is not a de Polignac number, because 21343254121 - 2³³ = 12753319529 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21343254121.

It is not an unprimeable number, because it can be changed into a prime (21343254131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41590 + ... + 210751.

It is an arithmetic number, because the mean of its divisors is an integer number (1565529768).

Almost surely, 2^21343254121 is an apocalyptic number.

It is an amenable number.

21343254121 is a deficient number, since it is larger than the sum of its proper divisors (3705222167).

21343254121 is a wasteful number, since it uses less digits than its factorization.

21343254121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252672.

The product of its digits is 5760, while the sum is 28.

Adding to 21343254121 its reverse (12145234312), we get a palindrome (33488488433).

The spelling of 21343254121 in words is "twenty-one billion, three hundred forty-three million, two hundred fifty-four thousand, one hundred twenty-one".