20918277457 has 8 divisors (see below), whose sum is σ = 26079930432. Its totient is φ = 16299956400.

The previous prime is 20918277439. The next prime is 20918277463. The reversal of 20918277457 is 75477281902.

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

It is not a de Polignac number, because 20918277457 - 2⁷ = 20918277329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20918277427) 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, 135832894 + ... + 135833047.

It is an arithmetic number, because the mean of its divisors is an integer number (3259991304).

Almost surely, 2^20918277457 is an apocalyptic number.

It is an amenable number.

20918277457 is a deficient number, since it is larger than the sum of its proper divisors (5161652975).

20918277457 is a wasteful number, since it uses less digits than its factorization.

20918277457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271665959.

The product of its (nonzero) digits is 1975680, while the sum is 52.

The spelling of 20918277457 in words is "twenty billion, nine hundred eighteen million, two hundred seventy-seven thousand, four hundred fifty-seven".