1977997 has 4 divisors (see below), whose sum is σ = 2260576. Its totient is φ = 1695420.

The previous prime is 1977991. The next prime is 1978021. The reversal of 1977997 is 7997791.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7997791 = 593 ⋅13487.

It is a cyclic number.

It is not a de Polignac number, because 1977997 - 2¹¹ = 1975949 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1977997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1977991) 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, 141279 + ... + 141292.

It is an arithmetic number, because the mean of its divisors is an integer number (565144).

2^1977997 is an apocalyptic number.

It is an amenable number.

1977997 is a deficient number, since it is larger than the sum of its proper divisors (282579).

1977997 is an equidigital number, since it uses as much as digits as its factorization.

1977997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282578.

The product of its digits is 250047, while the sum is 49.

The square root of 1977997 is about 1406.4128127972. The cubic root of 1977997 is about 125.5283661536.

The spelling of 1977997 in words is "one million, nine hundred seventy-seven thousand, nine hundred ninety-seven".