1971564 has 48 divisors (see below), whose sum is σ = 5376000. Its totient is φ = 562128.

The previous prime is 1971553. The next prime is 1971577. The reversal of 1971564 is 4651791.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3877 + ... + 4355.

It is an arithmetic number, because the mean of its divisors is an integer number (112000).

2^1971564 is an apocalyptic number.

1971564 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1971564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2688000).

1971564 is an abundant number, since it is smaller than the sum of its proper divisors (3404436).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1971564 is a wasteful number, since it uses less digits than its factorization.

1971564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507 (or 491 counting only the distinct ones).

The product of its digits is 7560, while the sum is 33.

The square root of 1971564 is about 1404.1239261547. The cubic root of 1971564 is about 125.3921338950.

The spelling of 1971564 in words is "one million, nine hundred seventy-one thousand, five hundred sixty-four".