21120034541 has 16 divisors (see below), whose sum is σ = 22526539056. Its totient is φ = 19732018176.

The previous prime is 21120034531. The next prime is 21120034543. The reversal of 21120034541 is 14543002112.

It can be written as a sum of positive squares in 8 ways, for example, as 629257225 + 20490777316 = 25085^2 + 143146^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120034541 - 2²² = 21115840237 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 (21120034543) 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, 3298355 + ... + 3304751.

It is an arithmetic number, because the mean of its divisors is an integer number (1407908691).

Almost surely, 2^21120034541 is an apocalyptic number.

It is an amenable number.

21120034541 is a deficient number, since it is larger than the sum of its proper divisors (1406504515).

21120034541 is a wasteful number, since it uses less digits than its factorization.

21120034541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7808.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21120034541 its reverse (14543002112), we get a palindrome (35663036653).

The spelling of 21120034541 in words is "twenty-one billion, one hundred twenty million, thirty-four thousand, five hundred forty-one".