20128337217 has 8 divisors (see below), whose sum is σ = 29819758880. Its totient is φ = 13418891460.

The previous prime is 20128337213. The next prime is 20128337261. The reversal of 20128337217 is 71273382102.

20128337217 is a `hidden beast` number, since 2 + 0 + 1 + 283 + 372 + 1 + 7 = 666.

It is not a de Polignac number, because 20128337217 - 2² = 20128337213 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20128337213) 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, 372746959 + ... + 372747012.

It is an arithmetic number, because the mean of its divisors is an integer number (3727469860).

Almost surely, 2^20128337217 is an apocalyptic number.

20128337217 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20128337217 is a deficient number, since it is larger than the sum of its proper divisors (9691421663).

20128337217 is an equidigital number, since it uses as much as digits as its factorization.

20128337217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745493980 (or 745493974 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The spelling of 20128337217 in words is "twenty billion, one hundred twenty-eight million, three hundred thirty-seven thousand, two hundred seventeen".