21420884534 has 16 divisors (see below), whose sum is σ = 36926668800. Its totient is φ = 9129090984.

The previous prime is 21420884531. The next prime is 21420884543. The reversal of 21420884534 is 43548802412.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21420884491 and 21420884500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420884531) 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 7 ways as a sum of consecutive naturals, for example, 4271414 + ... + 4276425.

It is an arithmetic number, because the mean of its divisors is an integer number (2307916800).

Almost surely, 2^21420884534 is an apocalyptic number.

21420884534 is a deficient number, since it is larger than the sum of its proper divisors (15505784266).

21420884534 is a wasteful number, since it uses less digits than its factorization.

21420884534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8548027.

The product of its (nonzero) digits is 245760, while the sum is 41.

The spelling of 21420884534 in words is "twenty-one billion, four hundred twenty million, eight hundred eighty-four thousand, five hundred thirty-four".