21204051235 has 8 divisors (see below), whose sum is σ = 25448952816. Its totient is φ = 16960513440.

The previous prime is 21204051203. The next prime is 21204051277. The reversal of 21204051235 is 53215040212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21204051235 - 2⁵ = 21204051203 is a prime.

It is a super-2 number, since 2×21204051235² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

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, 306421 + ... + 369190.

It is an arithmetic number, because the mean of its divisors is an integer number (3181119102).

Almost surely, 2^21204051235 is an apocalyptic number.

21204051235 is a deficient number, since it is larger than the sum of its proper divisors (4244901581).

21204051235 is an equidigital number, since it uses as much as digits as its factorization.

21204051235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681893.

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 21204051235 its reverse (53215040212), we get a palindrome (74419091447).

The spelling of 21204051235 in words is "twenty-one billion, two hundred four million, fifty-one thousand, two hundred thirty-five".