20872161997 has 8 divisors (see below), whose sum is σ = 20979150080. Its totient is φ = 20765293920.

The previous prime is 20872161953. The next prime is 20872162001. The reversal of 20872161997 is 79916127802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20872161997 - 2²³ = 20863773389 is a prime.

It is a super-2 number, since 2×20872161997² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20872161907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 329722 + ... + 387892.

It is an arithmetic number, because the mean of its divisors is an integer number (2622393760).

Almost surely, 2^20872161997 is an apocalyptic number.

It is an amenable number.

20872161997 is a deficient number, since it is larger than the sum of its proper divisors (106988083).

20872161997 is a wasteful number, since it uses less digits than its factorization.

20872161997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60003.

The product of its (nonzero) digits is 762048, while the sum is 52.

The spelling of 20872161997 in words is "twenty billion, eight hundred seventy-two million, one hundred sixty-one thousand, nine hundred ninety-seven".