19947285 has 12 divisors (see below), whose sum is σ = 34575372. Its totient is φ = 10638528.

The previous prime is 19947269. The next prime is 19947287. The reversal of 19947285 is 58274991.

It can be written as a sum of positive squares in 2 ways, for example, as 3617604 + 16329681 = 1902^2 + 4041^2 .

It is not a de Polignac number, because 19947285 - 2⁴ = 19947269 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 443273 = 19947285 / (1 + 9 + 9 + 4 + 7 + 2 + 8 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 19947285.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19947287) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 221592 + ... + 221681.

It is an arithmetic number, because the mean of its divisors is an integer number (2881281).

Almost surely, 2^19947285 is an apocalyptic number.

19947285 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19947285 is a deficient number, since it is larger than the sum of its proper divisors (14628087).

19947285 is a wasteful number, since it uses less digits than its factorization.

19947285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443284 (or 443281 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 19947285 is about 4466.2383501108. The cubic root of 19947285 is about 271.2030676161.

The spelling of 19947285 in words is "nineteen million, nine hundred forty-seven thousand, two hundred eighty-five".