1221153453 has 12 divisors (see below), whose sum is σ = 1899572220. Its totient is φ = 751478976.

The previous prime is 1221153433. The next prime is 1221153463. The reversal of 1221153453 is 3543511221.

1221153453 is a `hidden beast` number, since 122 + 1 + 1 + 534 + 5 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 130370724 + 1090782729 = 11418^2 + 33027^2 .

It is not a de Polignac number, because 1221153453 - 2⁹ = 1221152941 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221153413) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5218488 + ... + 5218721.

It is an arithmetic number, because the mean of its divisors is an integer number (158297685).

Almost surely, 2^1221153453 is an apocalyptic number.

1221153453 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1221153453 is a deficient number, since it is larger than the sum of its proper divisors (678418767).

1221153453 is a wasteful number, since it uses less digits than its factorization.

1221153453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10437228 (or 10437225 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 1221153453 is about 34945.0061239085. The cubic root of 1221153453 is about 1068.8663723902.

Adding to 1221153453 its reverse (3543511221), we get a palindrome (4764664674).

The spelling of 1221153453 in words is "one billion, two hundred twenty-one million, one hundred fifty-three thousand, four hundred fifty-three".