1221597 has 24 divisors (see below), whose sum is σ = 1945944. Its totient is φ = 733824.

The previous prime is 1221593. The next prime is 1221601. The reversal of 1221597 is 7951221.

It is an interprime number because it is at equal distance from previous prime (1221593) and next prime (1221601).

It can be written as a sum of positive squares in 4 ways, for example, as 427716 + 793881 = 654^2 + 891^2 .

It is not a de Polignac number, because 1221597 - 2² = 1221593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221597.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221593) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6103 + ... + 6299.

It is an arithmetic number, because the mean of its divisors is an integer number (81081).

2^1221597 is an apocalyptic number.

It is an amenable number.

1221597 is a deficient number, since it is larger than the sum of its proper divisors (724347).

1221597 is a wasteful number, since it uses less digits than its factorization.

1221597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 266 counting only the distinct ones).

The product of its digits is 1260, while the sum is 27.

The square root of 1221597 is about 1105.2587932245. The cubic root of 1221597 is about 106.8995767836.

It can be divided in two parts, 12 and 21597, that added together give a square (21609 = 147²).

The spelling of 1221597 in words is "one million, two hundred twenty-one thousand, five hundred ninety-seven".