1797981 has 8 divisors (see below), whose sum is σ = 2403744. Its totient is φ = 1195440.

The previous prime is 1797967. The next prime is 1798001. The reversal of 1797981 is 1897971.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1797981 - 2⁹ = 1797469 is a prime.

It is a super-2 number, since 2×1797981² = 6465471352722, which contains 22 as substring.

1797981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1797911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1251 + ... + 2271.

It is an arithmetic number, because the mean of its divisors is an integer number (300468).

2^1797981 is an apocalyptic number.

It is an amenable number.

1797981 is a deficient number, since it is larger than the sum of its proper divisors (605763).

1797981 is a wasteful number, since it uses less digits than its factorization.

1797981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1611.

The product of its digits is 31752, while the sum is 42.

The square root of 1797981 is about 1340.8881385112. Note that the first 3 decimals coincide. The cubic root of 1797981 is about 121.5985415410.

The spelling of 1797981 in words is "one million, seven hundred ninety-seven thousand, nine hundred eighty-one".