1211530531 has 8 divisors (see below), whose sum is σ = 1230759200. Its totient is φ = 1192449600.

The previous prime is 1211530511. The next prime is 1211530549. The reversal of 1211530531 is 1350351121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211530531 - 2¹⁹ = 1211006243 is a prime.

It is a super-2 number, since 2×1211530531² = 2935612455090283922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211530511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20346 + ... + 53263.

It is an arithmetic number, because the mean of its divisors is an integer number (153844900).

Almost surely, 2^1211530531 is an apocalyptic number.

1211530531 is a deficient number, since it is larger than the sum of its proper divisors (19228669).

1211530531 is a wasteful number, since it uses less digits than its factorization.

1211530531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73869.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 1211530531 is about 34807.0471456572. The cubic root of 1211530531 is about 1066.0513414722.

Adding to 1211530531 its reverse (1350351121), we get a palindrome (2561881652).

The spelling of 1211530531 in words is "one billion, two hundred eleven million, five hundred thirty thousand, five hundred thirty-one".