1977942349 has 4 divisors (see below), whose sum is σ = 1978167420. Its totient is φ = 1977717280.

The previous prime is 1977942331. The next prime is 1977942409. The reversal of 1977942349 is 9432497791.

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 204690249 + 1773252100 = 14307^2 + 42110^2 .

It is a cyclic number.

It is not a de Polignac number, because 1977942349 - 2¹⁵ = 1977909581 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 1977942349.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1977942149) 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, 98794 + ... + 117115.

It is an arithmetic number, because the mean of its divisors is an integer number (494541855).

Almost surely, 2^1977942349 is an apocalyptic number.

It is an amenable number.

1977942349 is a deficient number, since it is larger than the sum of its proper divisors (225071).

1977942349 is an equidigital number, since it uses as much as digits as its factorization.

1977942349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225070.

The product of its digits is 3429216, while the sum is 55.

The square root of 1977942349 is about 44474.0637787913. The cubic root of 1977942349 is about 1255.2721004903.

It can be divided in two parts, 19779 and 42349, that added together give a triangular number (62128 = T₃₅₂).

The spelling of 1977942349 in words is "one billion, nine hundred seventy-seven million, nine hundred forty-two thousand, three hundred forty-nine".