1971816 has 96 divisors (see below), whose sum is σ = 6256320. Its totient is φ = 506880.

The previous prime is 1971799. The next prime is 1971829. The reversal of 1971816 is 6181791.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20280 + ... + 20376.

It is an arithmetic number, because the mean of its divisors is an integer number (65170).

2^1971816 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 1971816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3128160).

1971816 is an abundant number, since it is smaller than the sum of its proper divisors (4284504).

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

1971816 is a wasteful number, since it uses less digits than its factorization.

1971816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 120 counting only the distinct ones).

The product of its digits is 3024, while the sum is 33.

The square root of 1971816 is about 1404.2136589565. The cubic root of 1971816 is about 125.3974760957.

The spelling of 1971816 in words is "one million, nine hundred seventy-one thousand, eight hundred sixteen".