155142985 has 4 divisors (see below), whose sum is σ = 186171588. Its totient is φ = 124114384.

The previous prime is 155142983. The next prime is 155143033. The reversal of 155142985 is 589241551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 589241551 = 113 ⋅5214527.

It can be written as a sum of positive squares in 2 ways, for example, as 101384761 + 53758224 = 10069^2 + 7332^2 .

It is a cyclic number.

It is not a de Polignac number, because 155142985 - 2¹ = 155142983 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155142983) 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, 15514294 + ... + 15514303.

It is an arithmetic number, because the mean of its divisors is an integer number (46542897).

Almost surely, 2^155142985 is an apocalyptic number.

It is an amenable number.

155142985 is a deficient number, since it is larger than the sum of its proper divisors (31028603).

155142985 is an equidigital number, since it uses as much as digits as its factorization.

155142985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31028602.

The product of its digits is 72000, while the sum is 40.

The square root of 155142985 is about 12455.6406900649. The cubic root of 155142985 is about 537.3336611663. Note that the first 3 decimals are identical.

The spelling of 155142985 in words is "one hundred fifty-five million, one hundred forty-two thousand, nine hundred eighty-five".