155781297 has 12 divisors (see below), whose sum is σ = 257162880. Its totient is φ = 89017848.

The previous prime is 155781287. The next prime is 155781337. The reversal of 155781297 is 792187551.

155781297 is a `hidden beast` number, since 1 + 557 + 8 + 1 + 2 + 97 = 666.

It is not a de Polignac number, because 155781297 - 2⁴ = 155781281 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (155781287) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1236297 + ... + 1236422.

It is an arithmetic number, because the mean of its divisors is an integer number (21430240).

Almost surely, 2^155781297 is an apocalyptic number.

It is an amenable number.

155781297 is a deficient number, since it is larger than the sum of its proper divisors (101381583).

155781297 is a wasteful number, since it uses less digits than its factorization.

155781297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2472732 (or 2472729 counting only the distinct ones).

The product of its digits is 176400, while the sum is 45.

The square root of 155781297 is about 12481.2377991928. The cubic root of 155781297 is about 538.0695784401.

The spelling of 155781297 in words is "one hundred fifty-five million, seven hundred eighty-one thousand, two hundred ninety-seven".