20772017555 has 4 divisors (see below), whose sum is σ = 24926421072. Its totient is φ = 16617614040.

The previous prime is 20772017551. The next prime is 20772017569. The reversal of 20772017555 is 55571027702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55571027702 = 2 ⋅27785513851.

It is not a de Polignac number, because 20772017555 - 2² = 20772017551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20772017551) 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 3 ways as a sum of consecutive naturals, for example, 2077201751 + ... + 2077201760.

It is an arithmetic number, because the mean of its divisors is an integer number (6231605268).

Almost surely, 2^20772017555 is an apocalyptic number.

20772017555 is a deficient number, since it is larger than the sum of its proper divisors (4154403517).

20772017555 is an equidigital number, since it uses as much as digits as its factorization.

20772017555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4154403516.

The product of its (nonzero) digits is 171500, while the sum is 41.

The spelling of 20772017555 in words is "twenty billion, seven hundred seventy-two million, seventeen thousand, five hundred fifty-five".