1221726 has 32 divisors (see below), whose sum is σ = 2706048. Its totient is φ = 364640.

The previous prime is 1221707. The next prime is 1221749. The reversal of 1221726 is 6271221.

It is a super-2 number, since 2×1221726² = 2985228838152, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6976 + ... + 7148.

It is an arithmetic number, because the mean of its divisors is an integer number (84564).

2^1221726 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221726, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1353024).

1221726 is an abundant number, since it is smaller than the sum of its proper divisors (1484322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221726 is a wasteful number, since it uses less digits than its factorization.

1221726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296.

The product of its digits is 336, while the sum is 21.

The square root of 1221726 is about 1105.3171490572. The cubic root of 1221726 is about 106.9033394975.

Adding to 1221726 its reverse (6271221), we get a palindrome (7492947).

It can be divided in two parts, 1221 and 726, that multiplied together give a triangular number (886446 = T₁₃₃₁).

The spelling of 1221726 in words is "one million, two hundred twenty-one thousand, seven hundred twenty-six".