21001515404 has 12 divisors (see below), whose sum is σ = 38687002200. Its totient is φ = 9948086208.

The previous prime is 21001515389. The next prime is 21001515407. The reversal of 21001515404 is 40451510012.

It is a self number, because there is not a number n which added to its sum of digits gives 21001515404.

It is not an unprimeable number, because it can be changed into a prime (21001515407) 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 in 3 ways as a sum of consecutive naturals, for example, 138167789 + ... + 138167940.

It is an arithmetic number, because the mean of its divisors is an integer number (3223916850).

Almost surely, 2^21001515404 is an apocalyptic number.

It is an amenable number.

21001515404 is a deficient number, since it is larger than the sum of its proper divisors (17685486796).

21001515404 is a wasteful number, since it uses less digits than its factorization.

21001515404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276335752 (or 276335750 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 23.

The spelling of 21001515404 in words is "twenty-one billion, one million, five hundred fifteen thousand, four hundred four".