1920997 has 4 divisors (see below), whose sum is σ = 2068780. Its totient is φ = 1773216.

The previous prime is 1920991. The next prime is 1921013. The reversal of 1920997 is 7990291.

It is a Cunningham number, because it is equal to 1386²+1.

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 285156 + 1635841 = 534^2 + 1279^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1920997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1920991) 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, 73872 + ... + 73897.

It is an arithmetic number, because the mean of its divisors is an integer number (517195).

2^1920997 is an apocalyptic number.

It is an amenable number.

1920997 is a deficient number, since it is larger than the sum of its proper divisors (147783).

1920997 is a wasteful number, since it uses less digits than its factorization.

1920997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147782.

The product of its (nonzero) digits is 10206, while the sum is 37.

The square root of 1920997 is about 1386.0003607503. Note that the first 3 decimals coincide. The cubic root of 1920997 is about 124.3108097850.

It can be divided in two parts, 19209 and 97, that added together give a triangular number (19306 = T₁₉₆).

The spelling of 1920997 in words is "one million, nine hundred twenty thousand, nine hundred ninety-seven".