21354544607721 has 8 divisors (see below), whose sum is σ = 30662935847040. Its totient is φ = 13141258220112.

The previous prime is 21354544607707. The next prime is 21354544607741. The reversal of 21354544607721 is 12770644545312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21354544607721 - 2²¹ = 21354542510569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21354544607741) 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, 273776212881 + ... + 273776212958.

It is an arithmetic number, because the mean of its divisors is an integer number (3832866980880).

Almost surely, 2^{21354544607721} is an apocalyptic number.

It is an amenable number.

21354544607721 is a deficient number, since it is larger than the sum of its proper divisors (9308391239319).

21354544607721 is a wasteful number, since it uses less digits than its factorization.

21354544607721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547552425855.

The product of its (nonzero) digits is 5644800, while the sum is 51.

The spelling of 21354544607721 in words is "twenty-one trillion, three hundred fifty-four billion, five hundred forty-four million, six hundred seven thousand, seven hundred twenty-one".