1601721155 has 8 divisors (see below), whose sum is σ = 1922281200. Its totient is φ = 1281233056.

The previous prime is 1601721139. The next prime is 1601721167. The reversal of 1601721155 is 5511271061.

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 1601721155 - 2⁴ = 1601721139 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 71276 + ... + 91014.

It is an arithmetic number, because the mean of its divisors is an integer number (240285150).

Almost surely, 2^1601721155 is an apocalyptic number.

1601721155 is a deficient number, since it is larger than the sum of its proper divisors (320560045).

1601721155 is a wasteful number, since it uses less digits than its factorization.

1601721155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35973.

The product of its (nonzero) digits is 2100, while the sum is 29.

The square root of 1601721155 is about 40021.5086547222. The cubic root of 1601721155 is about 1170.0263356382.

The spelling of 1601721155 in words is "one billion, six hundred one million, seven hundred twenty-one thousand, one hundred fifty-five".