1211455545 has 16 divisors (see below), whose sum is σ = 1944529152. Its totient is φ = 644042880.

The previous prime is 1211455537. The next prime is 1211455573. The reversal of 1211455545 is 5455541121.

It is a happy number.

It is not a de Polignac number, because 1211455545 - 2³ = 1211455537 is a prime.

It is a super-3 number, since 3×1211455545³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124321 + ... + 133710.

It is an arithmetic number, because the mean of its divisors is an integer number (121533072).

Almost surely, 2^1211455545 is an apocalyptic number.

1211455545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1211455545 is a deficient number, since it is larger than the sum of its proper divisors (733073607).

1211455545 is a wasteful number, since it uses less digits than its factorization.

1211455545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258352.

The product of its digits is 20000, while the sum is 33.

The square root of 1211455545 is about 34805.9699620625. The cubic root of 1211455545 is about 1066.0293470959.

Adding to 1211455545 its reverse (5455541121), we get a palindrome (6666996666).

The spelling of 1211455545 in words is "one billion, two hundred eleven million, four hundred fifty-five thousand, five hundred forty-five".