20494487 has 4 divisors (see below), whose sum is σ = 22071000. Its totient is φ = 18917976.

The previous prime is 20494433. The next prime is 20494493. The reversal of 20494487 is 78449402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78449402 = 2 ⋅39224701.

It is a cyclic number.

It is not a de Polignac number, because 20494487 - 2⁶ = 20494423 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20494487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20494427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 788237 + ... + 788262.

It is an arithmetic number, because the mean of its divisors is an integer number (5517750).

Almost surely, 2^20494487 is an apocalyptic number.

20494487 is a deficient number, since it is larger than the sum of its proper divisors (1576513).

20494487 is a wasteful number, since it uses less digits than its factorization.

20494487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1576512.

The product of its (nonzero) digits is 64512, while the sum is 38.

The square root of 20494487 is about 4527.0837191287. The cubic root of 20494487 is about 273.6606477774.

The spelling of 20494487 in words is "twenty million, four hundred ninety-four thousand, four hundred eighty-seven".