1216530 has 48 divisors (see below), whose sum is σ = 3616704. Its totient is φ = 277920.

The previous prime is 1216529. The next prime is 1216543. The reversal of 1216530 is 356121.

Added to its reverse (356121) it gives a triangular number (1572651 = T₁₇₇₃).

1216530 is a `hidden beast` number, since 12 + 1 + 653 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 336 + ... + 1595.

It is an arithmetic number, because the mean of its divisors is an integer number (75348).

2^1216530 is an apocalyptic number.

1216530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1216530 is an abundant number, since it is smaller than the sum of its proper divisors (2400174).

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

1216530 is a wasteful number, since it uses less digits than its factorization.

1216530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1951 (or 1948 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 1216530 is about 1102.9641879952. The cubic root of 1216530 is about 106.7515708552.

Adding to 1216530 its reverse (356121), we get a triangular number (1572651 = T₁₇₇₃).

The spelling of 1216530 in words is "one million, two hundred sixteen thousand, five hundred thirty".