154889993 has 4 divisors (see below), whose sum is σ = 156630420. Its totient is φ = 153149568.

The previous prime is 154889989. The next prime is 154890017. The reversal of 154889993 is 399988451.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 399988451 = 43 ⋅9302057.

It can be written as a sum of positive squares in 2 ways, for example, as 108826624 + 46063369 = 10432^2 + 6787^2 .

It is a cyclic number.

It is not a de Polignac number, because 154889993 - 2² = 154889989 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (154889963) 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, 870080 + ... + 870257.

It is an arithmetic number, because the mean of its divisors is an integer number (39157605).

Almost surely, 2^154889993 is an apocalyptic number.

It is an amenable number.

154889993 is a deficient number, since it is larger than the sum of its proper divisors (1740427).

154889993 is an equidigital number, since it uses as much as digits as its factorization.

154889993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1740426.

The product of its digits is 2799360, while the sum is 56.

The square root of 154889993 is about 12445.4808263883. The cubic root of 154889993 is about 537.0414252056.

The spelling of 154889993 in words is "one hundred fifty-four million, eight hundred eighty-nine thousand, nine hundred ninety-three".