153991009 has 4 divisors (see below), whose sum is σ = 154041520. Its totient is φ = 153940500.

The previous prime is 153990997. The next prime is 153991021. The reversal of 153991009 is 900199351.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 900199351 = 17 ⋅52952903.

It is an interprime number because it is at equal distance from previous prime (153990997) and next prime (153991021).

It is a cyclic number.

It is not a de Polignac number, because 153991009 - 2¹⁹ = 153466721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (153991069) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20367 + ... + 26884.

It is an arithmetic number, because the mean of its divisors is an integer number (38510380).

Almost surely, 2^153991009 is an apocalyptic number.

It is an amenable number.

153991009 is a deficient number, since it is larger than the sum of its proper divisors (50511).

153991009 is an equidigital number, since it uses as much as digits as its factorization.

153991009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50510.

The product of its (nonzero) digits is 10935, while the sum is 37.

The square root of 153991009 is about 12409.3113829898. The cubic root of 153991009 is about 536.0004095657. Note that the first 3 decimals are identical.

The spelling of 153991009 in words is "one hundred fifty-three million, nine hundred ninety-one thousand, nine".