21454355163809 has 4 divisors (see below), whose sum is σ = 21455929577904. Its totient is φ = 21452780749716.

The previous prime is 21454355163803. The next prime is 21454355163817. The reversal of 21454355163809 is 90836155345412.

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 a de Polignac number, because none of the positive numbers 2^k-21454355163809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21454355163803) 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, 787186607 + ... + 787213860.

It is an arithmetic number, because the mean of its divisors is an integer number (5363982394476).

Almost surely, 2^{21454355163809} is an apocalyptic number.

It is an amenable number.

21454355163809 is a deficient number, since it is larger than the sum of its proper divisors (1574414095).

21454355163809 is a wasteful number, since it uses less digits than its factorization.

21454355163809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1574414094.

The product of its (nonzero) digits is 15552000, while the sum is 56.

The spelling of 21454355163809 in words is "twenty-one trillion, four hundred fifty-four billion, three hundred fifty-five million, one hundred sixty-three thousand, eight hundred nine".