21420711288 has 48 divisors (see below), whose sum is σ = 58112374320. Its totient is φ = 7128182016.

The previous prime is 21420711271. The next prime is 21420711317. The reversal of 21420711288 is 88211702412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 11 ways as a sum of consecutive naturals, for example, 208156 + ... + 293547.

It is an arithmetic number, because the mean of its divisors is an integer number (1210674465).

Almost surely, 2^21420711288 is an apocalyptic number.

It is an amenable number.

21420711288 is an abundant number, since it is smaller than the sum of its proper divisors (36691663032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21420711288 is a wasteful number, since it uses less digits than its factorization.

21420711288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502308 (or 502301 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The spelling of 21420711288 in words is "twenty-one billion, four hundred twenty million, seven hundred eleven thousand, two hundred eighty-eight".