21145465121 has 8 divisors (see below), whose sum is σ = 23077695744. Its totient is φ = 19214887120.

The previous prime is 21145465097. The next prime is 21145465151. The reversal of 21145465121 is 12156454112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21145465121 - 2¹⁸ = 21145202977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21145465151) 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, 386321 + ... + 437646.

It is an arithmetic number, because the mean of its divisors is an integer number (2884711968).

Almost surely, 2^21145465121 is an apocalyptic number.

It is an amenable number.

21145465121 is a deficient number, since it is larger than the sum of its proper divisors (1932230623).

21145465121 is a wasteful number, since it uses less digits than its factorization.

21145465121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826311.

The product of its digits is 9600, while the sum is 32.

The spelling of 21145465121 in words is "twenty-one billion, one hundred forty-five million, four hundred sixty-five thousand, one hundred twenty-one".