21001554541 has 8 divisors (see below), whose sum is σ = 23906908224. Its totient is φ = 18262221120.

The previous prime is 21001554533. The next prime is 21001554551. The reversal of 21001554541 is 14545510012.

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

It is not a de Polignac number, because 21001554541 - 2³ = 21001554533 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 (21001554551) 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, 41504796 + ... + 41505301.

It is an arithmetic number, because the mean of its divisors is an integer number (2988363528).

Almost surely, 2^21001554541 is an apocalyptic number.

It is an amenable number.

21001554541 is a deficient number, since it is larger than the sum of its proper divisors (2905353683).

21001554541 is a wasteful number, since it uses less digits than its factorization.

21001554541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83010131.

The product of its (nonzero) digits is 4000, while the sum is 28.

The spelling of 21001554541 in words is "twenty-one billion, one million, five hundred fifty-four thousand, five hundred forty-one".