1971247 has 4 divisors (see below), whose sum is σ = 1977976. Its totient is φ = 1964520.

The previous prime is 1971241. The next prime is 1971251. The reversal of 1971247 is 7421791.

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 1971247 - 2⁷ = 1971119 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 (1971241) 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, 2904 + ... + 3517.

It is an arithmetic number, because the mean of its divisors is an integer number (494494).

2^1971247 is an apocalyptic number.

1971247 is a deficient number, since it is larger than the sum of its proper divisors (6729).

1971247 is an equidigital number, since it uses as much as digits as its factorization.

1971247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6728.

The product of its digits is 3528, while the sum is 31.

The square root of 1971247 is about 1404.0110398426. The cubic root of 1971247 is about 125.3854130993.

Subtracting from 1971247 its sum of digits (31), we obtain a square (1971216 = 1404²).

It can be divided in two parts, 197 and 1247, that added together give a square (1444 = 38²).

The spelling of 1971247 in words is "one million, nine hundred seventy-one thousand, two hundred forty-seven".