20815872001 has 2 divisors, whose sum is σ = 20815872002. Its totient is φ = 20815872000.

The previous prime is 20815871957. The next prime is 20815872053. The reversal of 20815872001 is 10027851802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18646175601 + 2169696400 = 136551^2 + 46580^2 .

It is a cyclic number.

It is not a de Polignac number, because 20815872001 - 2¹⁹ = 20815347713 is a prime.

It is not a weakly prime, because it can be changed into another prime (20815875001) 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 as a sum of consecutive naturals, namely, 10407936000 + 10407936001.

It is an arithmetic number, because the mean of its divisors is an integer number (10407936001).

Almost surely, 2^20815872001 is an apocalyptic number.

It is an amenable number.

20815872001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20815872001 is an equidigital number, since it uses as much as digits as its factorization.

20815872001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8960, while the sum is 34.

The spelling of 20815872001 in words is "twenty billion, eight hundred fifteen million, eight hundred seventy-two thousand, one".