1981275 has 12 divisors (see below), whose sum is σ = 3275832. Its totient is φ = 1056640.

The previous prime is 1981267. The next prime is 1981277. The reversal of 1981275 is 5721891.

It is not a de Polignac number, because 1981275 - 2³ = 1981267 is a prime.

It is a super-3 number, since 3×1981275³ = 23332191564855515625, which contains 333 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

1981275 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1981277) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13134 + ... + 13283.

It is an arithmetic number, because the mean of its divisors is an integer number (272986).

2^1981275 is an apocalyptic number.

1981275 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1981275 is a deficient number, since it is larger than the sum of its proper divisors (1294557).

1981275 is a wasteful number, since it uses less digits than its factorization.

1981275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26430 (or 26425 counting only the distinct ones).

The product of its digits is 5040, while the sum is 33.

The square root of 1981275 is about 1407.5777065583. The cubic root of 1981275 is about 125.5976710929.

The spelling of 1981275 in words is "one million, nine hundred eighty-one thousand, two hundred seventy-five".