20172797953 has 16 divisors (see below), whose sum is σ = 25166306304. Its totient is φ = 15709185360.

The previous prime is 20172797947. The next prime is 20172797987. The reversal of 20172797953 is 35979727102.

It is not a de Polignac number, because 20172797953 - 2¹³ = 20172789761 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20172797953.

It is not an unprimeable number, because it can be changed into a prime (20172797923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42226 + ... + 205252.

It is an arithmetic number, because the mean of its divisors is an integer number (1572894144).

Almost surely, 2^20172797953 is an apocalyptic number.

It is an amenable number.

20172797953 is a deficient number, since it is larger than the sum of its proper divisors (4993508351).

20172797953 is a wasteful number, since it uses less digits than its factorization.

20172797953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164652.

The product of its (nonzero) digits is 1666980, while the sum is 52.

The spelling of 20172797953 in words is "twenty billion, one hundred seventy-two million, seven hundred ninety-seven thousand, nine hundred fifty-three".