155978617 has 8 divisors (see below), whose sum is σ = 168373440. Its totient is φ = 144051600.

The previous prime is 155978597. The next prime is 155978633. The reversal of 155978617 is 716879551.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155978617 - 2²⁷ = 21760889 is a prime.

It is a super-3 number, since 3×155978617³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155778617) 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 7 ways as a sum of consecutive naturals, for example, 116259 + ... + 117592.

It is an arithmetic number, because the mean of its divisors is an integer number (21046680).

Almost surely, 2^155978617 is an apocalyptic number.

It is an amenable number.

155978617 is a deficient number, since it is larger than the sum of its proper divisors (12394823).

155978617 is a wasteful number, since it uses less digits than its factorization.

155978617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233903.

The product of its digits is 529200, while the sum is 49.

The square root of 155978617 is about 12489.1399623833. The cubic root of 155978617 is about 538.2966640944.

The spelling of 155978617 in words is "one hundred fifty-five million, nine hundred seventy-eight thousand, six hundred seventeen".