21110525213 has 2 divisors, whose sum is σ = 21110525214. Its totient is φ = 21110525212.

The previous prime is 21110525209. The next prime is 21110525231. The reversal of 21110525213 is 31252501112.

Together with next prime (21110525231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19339630489 + 1770894724 = 139067^2 + 42082^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110525213 - 2² = 21110525209 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21110525203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555262606 + 10555262607.

It is an arithmetic number, because the mean of its divisors is an integer number (10555262607).

Almost surely, 2^21110525213 is an apocalyptic number.

It is an amenable number.

21110525213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110525213 is an equidigital number, since it uses as much as digits as its factorization.

21110525213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 600, while the sum is 23.

The spelling of 21110525213 in words is "twenty-one billion, one hundred ten million, five hundred twenty-five thousand, two hundred thirteen".