1211355045 has 24 divisors (see below), whose sum is σ = 2150897112. Its totient is φ = 630297600.

The previous prime is 1211355023. The next prime is 1211355049. The reversal of 1211355045 is 5405531121.

1211355045 is a `hidden beast` number, since 1 + 21 + 135 + 504 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7403841 + 1203951204 = 2721^2 + 34698^2 .

It is not a de Polignac number, because 1211355045 - 2¹⁰ = 1211354021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211355049) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 326436 + ... + 330125.

It is an arithmetic number, because the mean of its divisors is an integer number (89620713).

Almost surely, 2^1211355045 is an apocalyptic number.

1211355045 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1211355045 is a deficient number, since it is larger than the sum of its proper divisors (939542067).

1211355045 is a wasteful number, since it uses less digits than its factorization.

1211355045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656613 (or 656610 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 1211355045 is about 34804.5262142728. The cubic root of 1211355045 is about 1065.9998677058. Note that the first 3 decimals are identical.

Adding to 1211355045 its reverse (5405531121), we get a palindrome (6616886166).

The spelling of 1211355045 in words is "one billion, two hundred eleven million, three hundred fifty-five thousand, forty-five".