21720320470 has 32 divisors (see below), whose sum is σ = 41456507616. Its totient is φ = 8165184000.

The previous prime is 21720320449. The next prime is 21720320471. The reversal of 21720320470 is 7402302712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21720320471) 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, 25020 + ... + 209920.

It is an arithmetic number, because the mean of its divisors is an integer number (1295515863).

Almost surely, 2^21720320470 is an apocalyptic number.

21720320470 is a deficient number, since it is larger than the sum of its proper divisors (19736187146).

21720320470 is a wasteful number, since it uses less digits than its factorization.

21720320470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185616.

The product of its (nonzero) digits is 4704, while the sum is 28.

The spelling of 21720320470 in words is "twenty-one billion, seven hundred twenty million, three hundred twenty thousand, four hundred seventy".