1213533009 has 24 divisors (see below), whose sum is σ = 1957638592. Its totient is φ = 746787600.

The previous prime is 1213532987. The next prime is 1213533019. The reversal of 1213533009 is 9003353121.

It is a happy number.

1213533009 is a `hidden beast` number, since 1 + 2 + 1 + 353 + 300 + 9 = 666.

It is not a de Polignac number, because 1213533009 - 2¹¹ = 1213530961 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1213533019) 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, 188917 + ... + 195234.

Almost surely, 2^1213533009 is an apocalyptic number.

It is an amenable number.

1213533009 is a deficient number, since it is larger than the sum of its proper divisors (744105583).

1213533009 is an equidigital number, since it uses as much as digits as its factorization.

1213533009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384179 (or 384167 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 27.

The square root of 1213533009 is about 34835.8006797605. The cubic root of 1213533009 is about 1066.6383590904.

The spelling of 1213533009 in words is "one billion, two hundred thirteen million, five hundred thirty-three thousand, nine".