1977949 has 4 divisors (see below), whose sum is σ = 1991200. Its totient is φ = 1964700.

The previous prime is 1977929. The next prime is 1977953. The reversal of 1977949 is 9497791.

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: 9497791 = 167 ⋅56873.

It is a cyclic number.

It is not a de Polignac number, because 1977949 - 2⁵ = 1977917 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1977899 and 1977908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1977929) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6399 + ... + 6700.

It is an arithmetic number, because the mean of its divisors is an integer number (497800).

2^1977949 is an apocalyptic number.

It is an amenable number.

1977949 is a deficient number, since it is larger than the sum of its proper divisors (13251).

1977949 is a wasteful number, since it uses less digits than its factorization.

1977949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13250.

The product of its digits is 142884, while the sum is 46.

The square root of 1977949 is about 1406.3957480027. The cubic root of 1977949 is about 125.5273507475.

It can be divided in two parts, 1977 and 949, that added together give a triangular number (2926 = T₇₆).

The spelling of 1977949 in words is "one million, nine hundred seventy-seven thousand, nine hundred forty-nine".