1216065931 has 2 divisors, whose sum is σ = 1216065932. Its totient is φ = 1216065930.

The previous prime is 1216065899. The next prime is 1216065937. The reversal of 1216065931 is 1395606121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1216065931 - 2⁵ = 1216065899 is a prime.

It is a super-2 number, since 2×1216065931² = 2957632697077793522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1216065937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608032965 + 608032966.

It is an arithmetic number, because the mean of its divisors is an integer number (608032966).

Almost surely, 2^1216065931 is an apocalyptic number.

1216065931 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216065931 is an equidigital number, since it uses as much as digits as its factorization.

1216065931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 1216065931 is about 34872.1368860585. The cubic root of 1216065931 is about 1067.3799497530.

The spelling of 1216065931 in words is "one billion, two hundred sixteen million, sixty-five thousand, nine hundred thirty-one".