21125471524 has 6 divisors (see below), whose sum is σ = 36969575174. Its totient is φ = 10562735760.

The previous prime is 21125471459. The next prime is 21125471527. The reversal of 21125471524 is 42517452112.

It can be written as a sum of positive squares in only one way, i.e., 20978625600 + 146845924 = 144840^2 + 12118^2 .

It is a super-2 number, since 2×21125471524² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21125471524.

It is not an unprimeable number, because it can be changed into a prime (21125471527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2640683937 + ... + 2640683944.

Almost surely, 2^21125471524 is an apocalyptic number.

It is an amenable number.

21125471524 is a deficient number, since it is larger than the sum of its proper divisors (15844103650).

21125471524 is a wasteful number, since it uses less digits than its factorization.

21125471524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5281367885 (or 5281367883 counting only the distinct ones).

The product of its digits is 22400, while the sum is 34.

The spelling of 21125471524 in words is "twenty-one billion, one hundred twenty-five million, four hundred seventy-one thousand, five hundred twenty-four".