1210721 has 8 divisors (see below), whose sum is σ = 1270080. Its totient is φ = 1152592.

The previous prime is 1210717. The next prime is 1210747. The reversal of 1210721 is 1270121.

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

It is a cyclic number.

It is not a de Polignac number, because 1210721 - 2² = 1210717 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1210696 and 1210705.

It is not an unprimeable number, because it can be changed into a prime (1210711) 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, 2156 + ... + 2658.

It is an arithmetic number, because the mean of its divisors is an integer number (158760).

2^1210721 is an apocalyptic number.

It is an amenable number.

1210721 is a deficient number, since it is larger than the sum of its proper divisors (59359).

1210721 is an equidigital number, since it uses as much as digits as its factorization.

1210721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615.

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 1210721 is about 1100.3276784667. The cubic root of 1210721 is about 106.5813847417.

Adding to 1210721 its reverse (1270121), we get a palindrome (2480842).

The spelling of 1210721 in words is "one million, two hundred ten thousand, seven hundred twenty-one".