1971864 has 80 divisors (see below), whose sum is σ = 5880600. Its totient is φ = 615168.

The previous prime is 1971857. The next prime is 1971869. The reversal of 1971864 is 4681791.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971869) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10927 + ... + 11105.

2^1971864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1971864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2940300).

1971864 is an abundant number, since it is smaller than the sum of its proper divisors (3908736).

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

1971864 is a wasteful number, since it uses less digits than its factorization.

1971864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 201 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 1971864 is about 1404.2307502686. The cubic root of 1971864 is about 125.3984936061.

The spelling of 1971864 in words is "one million, nine hundred seventy-one thousand, eight hundred sixty-four".