21611125435664 has 10 divisors (see below), whose sum is σ = 41871555531630. Its totient is φ = 10805562717824.

The previous prime is 21611125435661. The next prime is 21611125435673. The reversal of 21611125435664 is 46653452111612.

It can be written as a sum of positive squares in only one way, i.e., 15555136000000 + 6055989435664 = 3944000^2 + 2460892^2 .

It is not an unprimeable number, because it can be changed into a prime (21611125435661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 675347669849 + ... + 675347669880.

It is an arithmetic number, because the mean of its divisors is an integer number (4187155553163).

Almost surely, 2^{21611125435664} is an apocalyptic number.

It is an amenable number.

21611125435664 is a deficient number, since it is larger than the sum of its proper divisors (20260430095966).

21611125435664 is a wasteful number, since it uses less digits than its factorization.

21611125435664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350695339737 (or 1350695339731 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 47.

The spelling of 21611125435664 in words is "twenty-one trillion, six hundred eleven billion, one hundred twenty-five million, four hundred thirty-five thousand, six hundred sixty-four".