155949999 has 4 divisors (see below), whose sum is σ = 207933336. Its totient is φ = 103966664.

The previous prime is 155949979. The next prime is 155950007. The reversal of 155949999 is 999949551.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 155949999 - 2¹¹ = 155947951 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155949979) 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, 25991664 + ... + 25991669.

It is an arithmetic number, because the mean of its divisors is an integer number (51983334).

Almost surely, 2^155949999 is an apocalyptic number.

155949999 is a deficient number, since it is larger than the sum of its proper divisors (51983337).

155949999 is an equidigital number, since it uses as much as digits as its factorization.

155949999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51983336.

The product of its digits is 5904900, while the sum is 60.

The square root of 155949999 is about 12487.9941944253. The cubic root of 155949999 is about 538.2637409573.

The spelling of 155949999 in words is "one hundred fifty-five million, nine hundred forty-nine thousand, nine hundred ninety-nine".