20798457 has 4 divisors (see below), whose sum is σ = 27731280. Its totient is φ = 13865636.

The previous prime is 20798447. The next prime is 20798461. The reversal of 20798457 is 75489702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20798457 - 2²⁰ = 19749881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20798447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3466407 + ... + 3466412.

It is an arithmetic number, because the mean of its divisors is an integer number (6932820).

Almost surely, 2^20798457 is an apocalyptic number.

It is an amenable number.

20798457 is a deficient number, since it is larger than the sum of its proper divisors (6932823).

20798457 is an equidigital number, since it uses as much as digits as its factorization.

20798457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6932822.

The product of its (nonzero) digits is 141120, while the sum is 42.

The square root of 20798457 is about 4560.5325346937. The cubic root of 20798457 is about 275.0069728260.

The spelling of 20798457 in words is "twenty million, seven hundred ninety-eight thousand, four hundred fifty-seven".