21970206720 has 1200 divisors, whose sum is σ = 100484068608. Its totient is φ = 4459069440.

The previous prime is 21970206691. The next prime is 21970206721. The reversal of 21970206720 is 2760207912.

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

It is not an unprimeable number, because it can be changed into a prime (21970206721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 510935019 + ... + 510935061.

Almost surely, 2^21970206720 is an apocalyptic number.

21970206720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21970206720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50242034304).

21970206720 is an abundant number, since it is smaller than the sum of its proper divisors (78513861888).

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

21970206720 is an equidigital number, since it uses as much as digits as its factorization.

21970206720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The spelling of 21970206720 in words is "twenty-one billion, nine hundred seventy million, two hundred six thousand, seven hundred twenty".