20645223575515 has 64 divisors (see below), whose sum is σ = 31116011286528. Its totient is φ = 12774513945600.

The previous prime is 20645223575497. The next prime is 20645223575531. The reversal of 20645223575515 is 51557532254602.

It is not a de Polignac number, because 20645223575515 - 2¹⁵ = 20645223542747 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 959473537 + ... + 959495053.

It is an arithmetic number, because the mean of its divisors is an integer number (486187676352).

Almost surely, 2^{20645223575515} is an apocalyptic number.

20645223575515 is a deficient number, since it is larger than the sum of its proper divisors (10470787711013).

20645223575515 is a wasteful number, since it uses less digits than its factorization.

20645223575515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39868.

The product of its (nonzero) digits is 12600000, while the sum is 52.

The spelling of 20645223575515 in words is "twenty trillion, six hundred forty-five billion, two hundred twenty-three million, five hundred seventy-five thousand, five hundred fifteen".