21110685245585 has 32 divisors (see below), whose sum is σ = 27296381095200. Its totient is φ = 15580928563200.

The previous prime is 21110685245581. The next prime is 21110685245621. The reversal of 21110685245585 is 58554258601112.

It is a happy number.

It can be written as a sum of positive squares in 16 ways, for example, as 15457698730384 + 5652986515201 = 3931628^2 + 2377601^2 .

It is not a de Polignac number, because 21110685245585 - 2² = 21110685245581 is a prime.

It is a super-2 number, since 2×21110685245585² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21110685245581) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1478228645 + ... + 1478242925.

It is an arithmetic number, because the mean of its divisors is an integer number (853011909225).

Almost surely, 2^{21110685245585} is an apocalyptic number.

It is an amenable number.

21110685245585 is a deficient number, since it is larger than the sum of its proper divisors (6185695849615).

21110685245585 is a wasteful number, since it uses less digits than its factorization.

21110685245585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25109.

The product of its (nonzero) digits is 3840000, while the sum is 53.

The spelling of 21110685245585 in words is "twenty-one trillion, one hundred ten billion, six hundred eighty-five million, two hundred forty-five thousand, five hundred eighty-five".