1997155 has 8 divisors (see below), whose sum is σ = 2419632. Its totient is φ = 1582368.

The previous prime is 1997141. The next prime is 1997161. The reversal of 1997155 is 5517991.

It is a happy number.

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 1997155 - 2¹¹ = 1995107 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 1332 + ... + 2401.

It is an arithmetic number, because the mean of its divisors is an integer number (302454).

2^1997155 is an apocalyptic number.

1997155 is a deficient number, since it is larger than the sum of its proper divisors (422477).

1997155 is a wasteful number, since it uses less digits than its factorization.

1997155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3845.

The product of its digits is 14175, while the sum is 37.

The square root of 1997155 is about 1413.2073450135. The cubic root of 1997155 is about 125.9323353833.

The spelling of 1997155 in words is "one million, nine hundred ninety-seven thousand, one hundred fifty-five".