20872178977 has 8 divisors (see below), whose sum is σ = 22557727080. Its totient is φ = 19198058880.

The previous prime is 20872178969. The next prime is 20872178983. The reversal of 20872178977 is 77987127802.

It can be written as a sum of positive squares in 4 ways, for example, as 309136 + 20871869841 = 556^2 + 144471^2 .

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

It is not a de Polignac number, because 20872178977 - 2³ = 20872178969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20872178377) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2853202 + ... + 2860507.

It is an arithmetic number, because the mean of its divisors is an integer number (2819715885).

Almost surely, 2^20872178977 is an apocalyptic number.

It is an amenable number.

20872178977 is a deficient number, since it is larger than the sum of its proper divisors (1685548103).

20872178977 is a wasteful number, since it uses less digits than its factorization.

20872178977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5714003.

The product of its (nonzero) digits is 5531904, while the sum is 58.

The spelling of 20872178977 in words is "twenty billion, eight hundred seventy-two million, one hundred seventy-eight thousand, nine hundred seventy-seven".