21417257044 has 12 divisors (see below), whose sum is σ = 37493715924. Its totient is φ = 10704766784.

The previous prime is 21417257041. The next prime is 21417257089. The reversal of 21417257044 is 44075271412.

It can be written as a sum of positive squares in 2 ways, for example, as 8215247044 + 13202010000 = 90638^2 + 114900^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21417256994 and 21417257012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21417257041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 952939 + ... + 975154.

It is an arithmetic number, because the mean of its divisors is an integer number (3124476327).

Almost surely, 2^21417257044 is an apocalyptic number.

It is an amenable number.

21417257044 is a deficient number, since it is larger than the sum of its proper divisors (16076458880).

21417257044 is a wasteful number, since it uses less digits than its factorization.

21417257044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1930874 (or 1930872 counting only the distinct ones).

The product of its (nonzero) digits is 62720, while the sum is 37.

It can be divided in two parts, 214172 and 57044, that added together give a triangular number (271216 = T₇₃₆).

The spelling of 21417257044 in words is "twenty-one billion, four hundred seventeen million, two hundred fifty-seven thousand, forty-four".