1097721 has 12 divisors (see below), whose sum is σ = 1654848. Its totient is φ = 699864.

The previous prime is 1097717. The next prime is 1097729. The reversal of 1097721 is 1277901.

It is not a de Polignac number, because 1097721 - 2² = 1097717 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1097729) 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, 2445 + ... + 2858.

It is an arithmetic number, because the mean of its divisors is an integer number (137904).

2^1097721 is an apocalyptic number.

It is an amenable number.

1097721 is a deficient number, since it is larger than the sum of its proper divisors (557127).

1097721 is a wasteful number, since it uses less digits than its factorization.

1097721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5332 (or 5329 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 27.

The square root of 1097721 is about 1047.7218142236. The cubic root of 1097721 is about 103.1566723653.

The spelling of 1097721 in words is "one million, ninety-seven thousand, seven hundred twenty-one".