21403154121 has 4 divisors (see below), whose sum is σ = 28537538832. Its totient is φ = 14268769412.

The previous prime is 21403154093. The next prime is 21403154159. The reversal of 21403154121 is 12145130412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21403154121 - 2¹⁵ = 21403121353 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21403154091 and 21403154100.

It is not an unprimeable number, because it can be changed into a prime (21403144121) 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, 3567192351 + ... + 3567192356.

It is an arithmetic number, because the mean of its divisors is an integer number (7134384708).

Almost surely, 2^21403154121 is an apocalyptic number.

It is an amenable number.

21403154121 is a deficient number, since it is larger than the sum of its proper divisors (7134384711).

21403154121 is an equidigital number, since it uses as much as digits as its factorization.

21403154121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7134384710.

The product of its (nonzero) digits is 960, while the sum is 24.

Adding to 21403154121 its reverse (12145130412), we get a palindrome (33548284533).

The spelling of 21403154121 in words is "twenty-one billion, four hundred three million, one hundred fifty-four thousand, one hundred twenty-one".