21145353241 has 4 divisors (see below), whose sum is σ = 21145665232. Its totient is φ = 21145041252.

The previous prime is 21145353227. The next prime is 21145353263. The reversal of 21145353241 is 14235354112.

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 21145353241 - 2⁹ = 21145352729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21145353211) 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, 6711 + ... + 205756.

It is an arithmetic number, because the mean of its divisors is an integer number (5286416308).

Almost surely, 2^21145353241 is an apocalyptic number.

It is an amenable number.

21145353241 is a deficient number, since it is larger than the sum of its proper divisors (311991).

21145353241 is an equidigital number, since it uses as much as digits as its factorization.

21145353241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311990.

The product of its digits is 14400, while the sum is 31.

The spelling of 21145353241 in words is "twenty-one billion, one hundred forty-five million, three hundred fifty-three thousand, two hundred forty-one".