1211545481 has 2 divisors, whose sum is σ = 1211545482. Its totient is φ = 1211545480.

The previous prime is 1211545463. The next prime is 1211545537. The reversal of 1211545481 is 1845451121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1183360000 + 28185481 = 34400^2 + 5309^2 .

It is an emirp because it is prime and its reverse (1845451121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211545481 - 2²² = 1207351177 is a prime.

It is a super-2 number, since 2×1211545481² = 2935684905063042722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1211545381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605772740 + 605772741.

It is an arithmetic number, because the mean of its divisors is an integer number (605772741).

Almost surely, 2^1211545481 is an apocalyptic number.

It is an amenable number.

1211545481 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211545481 is an equidigital number, since it uses as much as digits as its factorization.

1211545481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6400, while the sum is 32.

The square root of 1211545481 is about 34807.2619003564. The cubic root of 1211545481 is about 1066.0557263946.

The spelling of 1211545481 in words is "one billion, two hundred eleven million, five hundred forty-five thousand, four hundred eighty-one".