20700721440 has 144 divisors (see below), whose sum is σ = 80732852928. Its totient is φ = 4731591168.

The previous prime is 20700721427. The next prime is 20700721451. The reversal of 20700721440 is 4412700702.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1016742 + ... + 1036901.

It is an arithmetic number, because the mean of its divisors is an integer number (560644812).

Almost surely, 2^20700721440 is an apocalyptic number.

20700721440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20700721440 is an abundant number, since it is smaller than the sum of its proper divisors (60032131488).

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

20700721440 is a wasteful number, since it uses less digits than its factorization.

20700721440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2053671 (or 2053660 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The spelling of 20700721440 in words is "twenty billion, seven hundred million, seven hundred twenty-one thousand, four hundred forty".