21003549994 has 16 divisors (see below), whose sum is σ = 36036295488. Its totient is φ = 8993968992.

The previous prime is 21003549989. The next prime is 21003550013. The reversal of 21003549994 is 49994530012.

It is a super-2 number, since 2×21003549994² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 612072 + ... + 645475.

It is an arithmetic number, because the mean of its divisors is an integer number (2252268468).

Almost surely, 2^21003549994 is an apocalyptic number.

21003549994 is a deficient number, since it is larger than the sum of its proper divisors (15032745494).

21003549994 is a wasteful number, since it uses less digits than its factorization.

21003549994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1258749.

The product of its (nonzero) digits is 349920, while the sum is 46.

The spelling of 21003549994 in words is "twenty-one billion, three million, five hundred forty-nine thousand, nine hundred ninety-four".