21305419291 has 8 divisors (see below), whose sum is σ = 23564414384. Its totient is φ = 19135012320.

The previous prime is 21305419277. The next prime is 21305419297. The reversal of 21305419291 is 19291450312.

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 21305419291 - 2²³ = 21297030683 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

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 21305419291.

It is not an unprimeable number, because it can be changed into a prime (21305419297) 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, 22146525 + ... + 22147486.

It is an arithmetic number, because the mean of its divisors is an integer number (2945551798).

Almost surely, 2^21305419291 is an apocalyptic number.

21305419291 is a deficient number, since it is larger than the sum of its proper divisors (2258995093).

21305419291 is a wasteful number, since it uses less digits than its factorization.

21305419291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44294061.

The product of its (nonzero) digits is 19440, while the sum is 37.

The spelling of 21305419291 in words is "twenty-one billion, three hundred five million, four hundred nineteen thousand, two hundred ninety-one".