1221112531 has 2 divisors, whose sum is σ = 1221112532. Its totient is φ = 1221112530.

The previous prime is 1221112489. The next prime is 1221112547. The reversal of 1221112531 is 1352111221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221112531 - 2¹¹ = 1221110483 is a prime.

It is a super-2 number, since 2×1221112531² = 2982231626730451922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221112499 and 1221112508.

It is not a weakly prime, because it can be changed into another prime (1221112561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610556265 + 610556266.

It is an arithmetic number, because the mean of its divisors is an integer number (610556266).

Almost surely, 2^1221112531 is an apocalyptic number.

1221112531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221112531 is an equidigital number, since it uses as much as digits as its factorization.

1221112531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120, while the sum is 19.

The square root of 1221112531 is about 34944.4205990026. The cubic root of 1221112531 is about 1068.8544326846.

Adding to 1221112531 its reverse (1352111221), we get a palindrome (2573223752).

It can be divided in two parts, 12211 and 12531, that added together give a palindrome (24742).

The spelling of 1221112531 in words is "one billion, two hundred twenty-one million, one hundred twelve thousand, five hundred thirty-one".