21621453627541 has 8 divisors (see below), whose sum is σ = 22220024194368. Its totient is φ = 21026274396000.

The previous prime is 21621453627517. The next prime is 21621453627547. The reversal of 21621453627541 is 14572635412612.

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 21621453627541 - 2¹⁷ = 21621453496469 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 (21621453627547) 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, 847820895 + ... + 847846396.

It is an arithmetic number, because the mean of its divisors is an integer number (2777503024296).

Almost surely, 2^{21621453627541} is an apocalyptic number.

It is an amenable number.

21621453627541 is a deficient number, since it is larger than the sum of its proper divisors (598570566827).

21621453627541 is a wasteful number, since it uses less digits than its factorization.

21621453627541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1695667643.

The product of its digits is 2419200, while the sum is 49.

The spelling of 21621453627541 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred fifty-three million, six hundred twenty-seven thousand, five hundred forty-one".