21621555030541 has 8 divisors (see below), whose sum is σ = 21651215143320. Its totient is φ = 21591899284032.

The previous prime is 21621555030511. The next prime is 21621555030547. The reversal of 21621555030541 is 14503055512612.

It can be written as a sum of positive squares in 4 ways, for example, as 942899260900 + 20678655769641 = 971030^2 + 4547379^2 .

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 21621555030541 - 2¹³ = 21621555022349 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21621555030494 and 21621555030503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621555030547) 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, 8881555 + ... + 11051023.

It is an arithmetic number, because the mean of its divisors is an integer number (2706401892915).

Almost surely, 2^{21621555030541} is an apocalyptic number.

It is an amenable number.

21621555030541 is a deficient number, since it is larger than the sum of its proper divisors (29660112779).

21621555030541 is a wasteful number, since it uses less digits than its factorization.

21621555030541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2183135.

The product of its (nonzero) digits is 180000, while the sum is 40.

The spelling of 21621555030541 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred fifty-five million, thirty thousand, five hundred forty-one".