1971644 has 6 divisors (see below), whose sum is σ = 3450384. Its totient is φ = 985820.

The previous prime is 1971637. The next prime is 1971647. The reversal of 1971644 is 4461791.

It is a self number, because there is not a number n which added to its sum of digits gives 1971644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 246452 + ... + 246459.

It is an arithmetic number, because the mean of its divisors is an integer number (575064).

2^1971644 is an apocalyptic number.

It is an amenable number.

1971644 is a deficient number, since it is larger than the sum of its proper divisors (1478740).

1971644 is a wasteful number, since it uses less digits than its factorization.

1971644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492915 (or 492913 counting only the distinct ones).

The product of its digits is 6048, while the sum is 32.

The square root of 1971644 is about 1404.1524133797. The cubic root of 1971644 is about 125.3938298811.

The spelling of 1971644 in words is "one million, nine hundred seventy-one thousand, six hundred forty-four".