1221723 has 10 divisors (see below), whose sum is σ = 1825164. Its totient is φ = 814428.

The previous prime is 1221707. The next prime is 1221749. The reversal of 1221723 is 3271221.

It is not a de Polignac number, because 1221723 - 2⁴ = 1221707 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221696 and 1221705.

It is not an unprimeable number, because it can be changed into a prime (1221793) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 7461 + ... + 7622.

2^1221723 is an apocalyptic number.

1221723 is a deficient number, since it is larger than the sum of its proper divisors (603441).

1221723 is an equidigital number, since it uses as much as digits as its factorization.

1221723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15095 (or 15086 counting only the distinct ones).

The product of its digits is 168, while the sum is 18.

The square root of 1221723 is about 1105.3157919798. The cubic root of 1221723 is about 106.9032519955.

Adding to 1221723 its reverse (3271221), we get a palindrome (4492944).

The spelling of 1221723 in words is "one million, two hundred twenty-one thousand, seven hundred twenty-three".