21435420056 has 16 divisors (see below), whose sum is σ = 40195524240. Its totient is φ = 10716613600.

The previous prime is 21435420029. The next prime is 21435420067. The reversal of 21435420056 is 65002453412.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 50771 + ... + 213186.

It is an arithmetic number, because the mean of its divisors is an integer number (2512220265).

Almost surely, 2^21435420056 is an apocalyptic number.

It is an amenable number.

21435420056 is a deficient number, since it is larger than the sum of its proper divisors (18760104184).

21435420056 is a wasteful number, since it uses less digits than its factorization.

21435420056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274114 (or 274110 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 21435420056 its reverse (65002453412), we get a palindrome (86437873468).

The spelling of 21435420056 in words is "twenty-one billion, four hundred thirty-five million, four hundred twenty thousand, fifty-six".