20457671 has 4 divisors (see below), whose sum is σ = 22031352. Its totient is φ = 18883992.

The previous prime is 20457617. The next prime is 20457677. The reversal of 20457671 is 17675402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20457671 - 2²² = 16263367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20457677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 786821 + ... + 786846.

It is an arithmetic number, because the mean of its divisors is an integer number (5507838).

Almost surely, 2^20457671 is an apocalyptic number.

20457671 is a deficient number, since it is larger than the sum of its proper divisors (1573681).

20457671 is a wasteful number, since it uses less digits than its factorization.

20457671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573680.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 20457671 is about 4523.0156975186. The cubic root of 20457671 is about 273.4966828804.

It can be divided in two parts, 204 and 57671, that added together give a palindrome (57875).

The spelling of 20457671 in words is "twenty million, four hundred fifty-seven thousand, six hundred seventy-one".