155006781 has 4 divisors (see below), whose sum is σ = 206675712. Its totient is φ = 103337852.

The previous prime is 155006759. The next prime is 155006783. The reversal of 155006781 is 187600551.

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.

It is a cyclic number.

It is not a de Polignac number, because 155006781 - 2⁵ = 155006749 is a prime.

It is a super-2 number, since 2×155006781² = 48054204311963922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155006783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25834461 + ... + 25834466.

It is an arithmetic number, because the mean of its divisors is an integer number (51668928).

Almost surely, 2^155006781 is an apocalyptic number.

It is an amenable number.

155006781 is a deficient number, since it is larger than the sum of its proper divisors (51668931).

155006781 is an equidigital number, since it uses as much as digits as its factorization.

155006781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51668930.

The product of its (nonzero) digits is 8400, while the sum is 33.

The square root of 155006781 is about 12450.1719265237. The cubic root of 155006781 is about 537.1763687993.

The spelling of 155006781 in words is "one hundred fifty-five million, six thousand, seven hundred eighty-one".