20720646125 has 32 divisors (see below), whose sum is σ = 26352563328. Its totient is φ = 16262400000.

The previous prime is 20720646077. The next prime is 20720646151. The reversal of 20720646125 is 52164602702.

It is a de Polignac number, because none of the positive numbers 2^k-20720646125 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2097197 + ... + 2107053.

It is an arithmetic number, because the mean of its divisors is an integer number (823517604).

Almost surely, 2^20720646125 is an apocalyptic number.

20720646125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20720646125 is a deficient number, since it is larger than the sum of its proper divisors (5631917203).

20720646125 is an equidigital number, since it uses as much as digits as its factorization.

20720646125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10190 (or 10180 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The spelling of 20720646125 in words is "twenty billion, seven hundred twenty million, six hundred forty-six thousand, one hundred twenty-five".