155902993 has 8 divisors (see below), whose sum is σ = 166465728. Its totient is φ = 145655664.

The previous prime is 155902987. The next prime is 155902997. The reversal of 155902993 is 399209551.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155902993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is not an unprimeable number, because it can be changed into a prime (155902997) 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 7 ways as a sum of consecutive naturals, for example, 77830 + ... + 79807.

It is an arithmetic number, because the mean of its divisors is an integer number (20808216).

Almost surely, 2^155902993 is an apocalyptic number.

It is an amenable number.

155902993 is a deficient number, since it is larger than the sum of its proper divisors (10562735).

155902993 is a wasteful number, since it uses less digits than its factorization.

155902993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157703.

The product of its (nonzero) digits is 109350, while the sum is 43.

The square root of 155902993 is about 12486.1120049437. The cubic root of 155902993 is about 538.2096548868.

The spelling of 155902993 in words is "one hundred fifty-five million, nine hundred two thousand, nine hundred ninety-three".