1980155 has 4 divisors (see below), whose sum is σ = 2376192. Its totient is φ = 1584120.

The previous prime is 1980113. The next prime is 1980169. The reversal of 1980155 is 5510891.

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

It is not a de Polignac number, because 1980155 - 2⁸ = 1979899 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198011 + ... + 198020.

It is an arithmetic number, because the mean of its divisors is an integer number (594048).

2^1980155 is an apocalyptic number.

1980155 is a deficient number, since it is larger than the sum of its proper divisors (396037).

1980155 is an equidigital number, since it uses as much as digits as its factorization.

1980155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396036.

The product of its (nonzero) digits is 1800, while the sum is 29.

The square root of 1980155 is about 1407.1798037209. The cubic root of 1980155 is about 125.5740001560.

The spelling of 1980155 in words is "one million, nine hundred eighty thousand, one hundred fifty-five".