1971918 has 48 divisors (see below), whose sum is σ = 4809840. Its totient is φ = 595296.

The previous prime is 1971911. The next prime is 1971967. The reversal of 1971918 is 8191791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971911) 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, 37180 + ... + 37232.

It is an arithmetic number, because the mean of its divisors is an integer number (100205).

2^1971918 is an apocalyptic number.

1971918 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1971918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2404920).

1971918 is an abundant number, since it is smaller than the sum of its proper divisors (2837922).

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

1971918 is a wasteful number, since it uses less digits than its factorization.

1971918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 71 counting only the distinct ones).

The product of its digits is 4536, while the sum is 36.

The square root of 1971918 is about 1404.2499777461. The cubic root of 1971918 is about 125.3996382856.

The spelling of 1971918 in words is "one million, nine hundred seventy-one thousand, nine hundred eighteen".