155158721 has 8 divisors (see below), whose sum is σ = 156414720. Its totient is φ = 153908208.

The previous prime is 155158709. The next prime is 155158727. The reversal of 155158721 is 127851551.

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-155158721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155158727) 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, 69200 + ... + 71406.

It is an arithmetic number, because the mean of its divisors is an integer number (19551840).

Almost surely, 2^155158721 is an apocalyptic number.

It is an amenable number.

155158721 is a deficient number, since it is larger than the sum of its proper divisors (1255999).

155158721 is a wasteful number, since it uses less digits than its factorization.

155158721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2743.

The product of its digits is 14000, while the sum is 35.

The square root of 155158721 is about 12456.2723557250. The cubic root of 155158721 is about 537.3518276266.

The spelling of 155158721 in words is "one hundred fifty-five million, one hundred fifty-eight thousand, seven hundred twenty-one".