20494657 has 4 divisors (see below), whose sum is σ = 20505600. Its totient is φ = 20483716.

The previous prime is 20494651. The next prime is 20494667. The reversal of 20494657 is 75649402.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 75649402 = 2 ⋅37824701.

It is a cyclic number.

It is not a de Polignac number, because 20494657 - 2²³ = 12106049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20494651) 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, 1873 + ... + 6670.

It is an arithmetic number, because the mean of its divisors is an integer number (5126400).

Almost surely, 2^20494657 is an apocalyptic number.

It is an amenable number.

20494657 is a deficient number, since it is larger than the sum of its proper divisors (10943).

20494657 is an equidigital number, since it uses as much as digits as its factorization.

20494657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10942.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 20494657 is about 4527.1024949740. The cubic root of 20494657 is about 273.6614044392.

The spelling of 20494657 in words is "twenty million, four hundred ninety-four thousand, six hundred fifty-seven".