21554120541 has 16 divisors (see below), whose sum is σ = 29669971968. Its totient is φ = 13903969200.

The previous prime is 21554120509. The next prime is 21554120561. The reversal of 21554120541 is 14502145512.

It is not a de Polignac number, because 21554120541 - 2⁵ = 21554120509 is a prime.

It is a super-2 number, since 2×21554120541² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21554120499 and 21554120508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554120561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1028530 + ... + 1049276.

It is an arithmetic number, because the mean of its divisors is an integer number (1854373248).

Almost surely, 2^21554120541 is an apocalyptic number.

It is an amenable number.

21554120541 is a deficient number, since it is larger than the sum of its proper divisors (8115851427).

21554120541 is a wasteful number, since it uses less digits than its factorization.

21554120541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31952.

The product of its (nonzero) digits is 8000, while the sum is 30.

The spelling of 21554120541 in words is "twenty-one billion, five hundred fifty-four million, one hundred twenty thousand, five hundred forty-one".