21154372111 has 2 divisors, whose sum is σ = 21154372112. Its totient is φ = 21154372110.

The previous prime is 21154372097. The next prime is 21154372157. The reversal of 21154372111 is 11127345112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21154372111 - 2¹⁷ = 21154241039 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21154372111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21154372411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577186055 + 10577186056.

It is an arithmetic number, because the mean of its divisors is an integer number (10577186056).

Almost surely, 2^21154372111 is an apocalyptic number.

21154372111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21154372111 is an equidigital number, since it uses as much as digits as its factorization.

21154372111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 28.

The spelling of 21154372111 in words is "twenty-one billion, one hundred fifty-four million, three hundred seventy-two thousand, one hundred eleven".