1971858 has 48 divisors (see below), whose sum is σ = 4842720. Its totient is φ = 532224.

The previous prime is 1971857. The next prime is 1971869. The reversal of 1971858 is 8581791.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1971857) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5410 + ... + 5762.

It is an arithmetic number, because the mean of its divisors is an integer number (100890).

2^1971858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1971858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2421360).

1971858 is an abundant number, since it is smaller than the sum of its proper divisors (2870862).

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

1971858 is a wasteful number, since it uses less digits than its factorization.

1971858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391 (or 384 counting only the distinct ones).

The product of its digits is 20160, while the sum is 39.

The square root of 1971858 is about 1404.2286138660. The cubic root of 1971858 is about 125.3983664182.

The spelling of 1971858 in words is "one million, nine hundred seventy-one thousand, eight hundred fifty-eight".