155816397 has 24 divisors (see below), whose sum is σ = 258454560. Its totient is φ = 89462880.

The previous prime is 155816393. The next prime is 155816399. The reversal of 155816397 is 793618551.

It is a happy number.

155816397 is a `hidden beast` number, since 1 + 5 + 5 + 8 + 1 + 639 + 7 = 666.

It is not a de Polignac number, because 155816397 - 2² = 155816393 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155816393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39538 + ... + 43299.

It is an arithmetic number, because the mean of its divisors is an integer number (10768940).

Almost surely, 2^155816397 is an apocalyptic number.

It is an amenable number.

155816397 is a deficient number, since it is larger than the sum of its proper divisors (102638163).

155816397 is a wasteful number, since it uses less digits than its factorization.

155816397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82873 (or 82870 counting only the distinct ones).

The product of its digits is 226800, while the sum is 45.

The square root of 155816397 is about 12482.6438305353. The cubic root of 155816397 is about 538.1099872788.

It can be divided in two parts, 1558 and 16397, that added together give a triangular number (17955 = T₁₈₉).

The spelling of 155816397 in words is "one hundred fifty-five million, eight hundred sixteen thousand, three hundred ninety-seven".