1216557 has 6 divisors (see below), whose sum is σ = 1757262. Its totient is φ = 811032.

The previous prime is 1216547. The next prime is 1216559. The reversal of 1216557 is 7556121.

1216557 is a `hidden beast` number, since 1 + 2 + 1 + 655 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1212201 + 4356 = 1101^2 + 66^2 .

It is not a de Polignac number, because 1216557 - 2¹⁶ = 1151021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1216557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67578 + ... + 67595.

It is an arithmetic number, because the mean of its divisors is an integer number (292877).

2^1216557 is an apocalyptic number.

It is an amenable number.

1216557 is a deficient number, since it is larger than the sum of its proper divisors (540705).

1216557 is a wasteful number, since it uses less digits than its factorization.

1216557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135179 (or 135176 counting only the distinct ones).

The product of its digits is 2100, while the sum is 27.

The square root of 1216557 is about 1102.9764276720. The cubic root of 1216557 is about 106.7523606072.

It can be divided in two parts, 121 and 6557, that multiplied together give a palindrome (793397).

The spelling of 1216557 in words is "one million, two hundred sixteen thousand, five hundred fifty-seven".