21619455493 has 4 divisors (see below), whose sum is σ = 21660793408. Its totient is φ = 21578117580.

The previous prime is 21619455469. The next prime is 21619455497. The reversal of 21619455493 is 39455491612.

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 21619455493 - 2⁹ = 21619454981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21619455497) 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, 20668173 + ... + 20669218.

It is an arithmetic number, because the mean of its divisors is an integer number (5415198352).

Almost surely, 2^21619455493 is an apocalyptic number.

It is an amenable number.

21619455493 is a deficient number, since it is larger than the sum of its proper divisors (41337915).

21619455493 is an equidigital number, since it uses as much as digits as its factorization.

21619455493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41337914.

The product of its digits is 1166400, while the sum is 49.

The spelling of 21619455493 in words is "twenty-one billion, six hundred nineteen million, four hundred fifty-five thousand, four hundred ninety-three".