155388493 has 8 divisors (see below), whose sum is σ = 171864728. Its totient is φ = 139558464.

The previous prime is 155388491. The next prime is 155388539. The reversal of 155388493 is 394883551.

It can be written as a sum of positive squares in 4 ways, for example, as 61434244 + 93954249 = 7838^2 + 9693^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155388493 - 2¹ = 155388491 is a prime.

It is a super-2 number, since 2×155388493² = 48291167513622098, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155388491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161046 + ... + 162007.

It is an arithmetic number, because the mean of its divisors is an integer number (21483091).

Almost surely, 2^155388493 is an apocalyptic number.

155388493 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

155388493 is a deficient number, since it is larger than the sum of its proper divisors (16476235).

155388493 is a wasteful number, since it uses less digits than its factorization.

155388493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323103.

The product of its digits is 518400, while the sum is 46.

The square root of 155388493 is about 12465.4920881608. The cubic root of 155388493 is about 537.6169486287.

The spelling of 155388493 in words is "one hundred fifty-five million, three hundred eighty-eight thousand, four hundred ninety-three".