18920247 has 8 divisors (see below), whose sum is σ = 25251840. Its totient is φ = 12601080.

The previous prime is 18920233. The next prime is 18920249. The reversal of 18920247 is 74202981.

It is a happy number.

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

It is not a de Polignac number, because 18920247 - 2¹¹ = 18918199 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18920249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1372 + ... + 6302.

It is an arithmetic number, because the mean of its divisors is an integer number (3156480).

Almost surely, 2^18920247 is an apocalyptic number.

18920247 is a deficient number, since it is larger than the sum of its proper divisors (6331593).

18920247 is a wasteful number, since it uses less digits than its factorization.

18920247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6213.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 18920247 is about 4349.7410267739. The cubic root of 18920247 is about 266.4662850550.

The spelling of 18920247 in words is "eighteen million, nine hundred twenty thousand, two hundred forty-seven".