21004233985 has 16 divisors (see below), whose sum is σ = 29735027712. Its totient is φ = 13938292800.

The previous prime is 21004233977. The next prime is 21004233989. The reversal of 21004233985 is 58933240012.

It is not a de Polignac number, because 21004233985 - 2³ = 21004233977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21004233989) 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 15 ways as a sum of consecutive naturals, for example, 9678286 + ... + 9680455.

It is an arithmetic number, because the mean of its divisors is an integer number (1858439232).

Almost surely, 2^21004233985 is an apocalyptic number.

It is an amenable number.

21004233985 is a deficient number, since it is larger than the sum of its proper divisors (8730793727).

21004233985 is a wasteful number, since it uses less digits than its factorization.

21004233985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19358784.

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 21004233985 its reverse (58933240012), we get a palindrome (79937473997).

The spelling of 21004233985 in words is "twenty-one billion, four million, two hundred thirty-three thousand, nine hundred eighty-five".