1271820 has 96 divisors (see below), whose sum is σ = 4064256. Its totient is φ = 294400.

The previous prime is 1271813. The next prime is 1271827. The reversal of 1271820 is 281721.

It is an interprime number because it is at equal distance from previous prime (1271813) and next prime (1271827).

It is a super-2 number, since 2×1271820² = 3235052224800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1271827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27037 + ... + 27083.

It is an arithmetic number, because the mean of its divisors is an integer number (42336).

2^1271820 is an apocalyptic number.

1271820 is a gapful number since it is divisible by the number (10) 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 1271820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2032128).

1271820 is an abundant number, since it is smaller than the sum of its proper divisors (2792436).

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

1271820 is a wasteful number, since it uses less digits than its factorization.

1271820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 1271820 is about 1127.7499722900. The cubic root of 1271820 is about 108.3449192080.

Subtracting from 1271820 its reverse (281721), we obtain a palindrome (990099).

The spelling of 1271820 in words is "one million, two hundred seventy-one thousand, eight hundred twenty".