20778773147172 has 48 divisors (see below), whose sum is σ = 55728510364800. Its totient is φ = 6687421241760.

The previous prime is 20778773147149. The next prime is 20778773147177. The reversal of 20778773147172 is 27174137787702.

20778773147172 is a `hidden beast` number, since 2 + 0 + 77 + 87 + 7 + 314 + 7 + 172 = 666.

It is not an unprimeable number, because it can be changed into a prime (20778773147177) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3317170104 + ... + 3317176367.

It is an arithmetic number, because the mean of its divisors is an integer number (1161010632600).

Almost surely, 2^{20778773147172} is an apocalyptic number.

It is an amenable number.

20778773147172 is an abundant number, since it is smaller than the sum of its proper divisors (34949737217628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20778773147172 is a wasteful number, since it uses less digits than its factorization.

20778773147172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6634346513 (or 6634346505 counting only the distinct ones).

The product of its (nonzero) digits is 45177216, while the sum is 63.

The spelling of 20778773147172 in words is "twenty trillion, seven hundred seventy-eight billion, seven hundred seventy-three million, one hundred forty-seven thousand, one hundred seventy-two".