21541255511 has 2 divisors, whose sum is σ = 21541255512. Its totient is φ = 21541255510.

The previous prime is 21541255507. The next prime is 21541255579. The reversal of 21541255511 is 11555214512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21541255511 - 2² = 21541255507 is a prime.

It is a super-2 number, since 2×21541255511² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21541255501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770627755 + 10770627756.

It is an arithmetic number, because the mean of its divisors is an integer number (10770627756).

Almost surely, 2^21541255511 is an apocalyptic number.

21541255511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21541255511 is an equidigital number, since it uses as much as digits as its factorization.

21541255511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10000, while the sum is 32.

The spelling of 21541255511 in words is "twenty-one billion, five hundred forty-one million, two hundred fifty-five thousand, five hundred eleven".