155978381 has 12 divisors (see below), whose sum is σ = 169305012. Its totient is φ = 143634816.

The previous prime is 155978377. The next prime is 155978393. The reversal of 155978381 is 183879551.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 68724100 + 87254281 = 8290^2 + 9341^2 .

It is not a de Polignac number, because 155978381 - 2² = 155978377 is a prime.

It is a super-2 number, since 2×155978381² = 48658510678762322, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (302400) is a multiple of the sum of its prime factors (2240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155978321) 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 11 ways as a sum of consecutive naturals, for example, 93305 + ... + 94961.

It is an arithmetic number, because the mean of its divisors is an integer number (14108751).

Almost surely, 2^155978381 is an apocalyptic number.

It is an amenable number.

155978381 is a deficient number, since it is larger than the sum of its proper divisors (13326631).

155978381 is a wasteful number, since it uses less digits than its factorization.

155978381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2240 (or 2227 counting only the distinct ones).

The product of its digits is 302400, while the sum is 47.

The square root of 155978381 is about 12489.1305141711. The cubic root of 155978381 is about 538.2963926083.

The spelling of 155978381 in words is "one hundred fifty-five million, nine hundred seventy-eight thousand, three hundred eighty-one".