21409519643 has 8 divisors (see below), whose sum is σ = 21773516688. Its totient is φ = 21047433984.

The previous prime is 21409519633. The next prime is 21409519657. The reversal of 21409519643 is 34691590412.

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 21409519643 - 2⁴ = 21409519627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21409519594 and 21409519603.

It is not an unprimeable number, because it can be changed into a prime (21409519603) 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, 455246 + ... + 500067.

It is an arithmetic number, because the mean of its divisors is an integer number (2721689586).

Almost surely, 2^21409519643 is an apocalyptic number.

21409519643 is a deficient number, since it is larger than the sum of its proper divisors (363997045).

21409519643 is an equidigital number, since it uses as much as digits as its factorization.

21409519643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 955693.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 21409519643 in words is "twenty-one billion, four hundred nine million, five hundred nineteen thousand, six hundred forty-three".