156000055170721 has 4 divisors (see below), whose sum is σ = 156154663749700. Its totient is φ = 155845446591744.

The previous prime is 156000055170719. The next prime is 156000055170731. The reversal of 156000055170721 is 127071550000651.

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

It can be written as a sum of positive squares in 2 ways, for example, as 81304846286400 + 74695208884321 = 9016920^2 + 8642639^2 .

It is a cyclic number.

It is not a de Polignac number, because 156000055170721 - 2¹ = 156000055170719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (156000055170731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77304287976 + ... + 77304289993.

It is an arithmetic number, because the mean of its divisors is an integer number (39038665937425).

Almost surely, 2^{156000055170721} is an apocalyptic number.

It is an amenable number.

156000055170721 is a deficient number, since it is larger than the sum of its proper divisors (154608578979).

156000055170721 is a wasteful number, since it uses less digits than its factorization.

156000055170721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154608578978.

The product of its (nonzero) digits is 73500, while the sum is 40.

The spelling of 156000055170721 in words is "one hundred fifty-six trillion, fifty-five million, one hundred seventy thousand, seven hundred twenty-one".