21154510221541 has 8 divisors (see below), whose sum is σ = 21423046627584. Its totient is φ = 20886299120160.

The previous prime is 21154510221457. The next prime is 21154510221589. The reversal of 21154510221541 is 14512201545112.

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 21154510221541 - 2²⁵ = 21154476667109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21154510221497 and 21154510221506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154510227541) 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, 81195280 + ... + 81455401.

It is an arithmetic number, because the mean of its divisors is an integer number (2677880828448).

Almost surely, 2^{21154510221541} is an apocalyptic number.

It is an amenable number.

21154510221541 is a deficient number, since it is larger than the sum of its proper divisors (268536406043).

21154510221541 is a wasteful number, since it uses less digits than its factorization.

21154510221541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162652331.

The product of its (nonzero) digits is 16000, while the sum is 34.

Adding to 21154510221541 its reverse (14512201545112), we get a palindrome (35666711766653).

The spelling of 21154510221541 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred ten million, two hundred twenty-one thousand, five hundred forty-one".