1978829957 has 6 divisors (see below), whose sum is σ = 2142756882. Its totient is φ = 1826612112.

The previous prime is 1978829953. The next prime is 1978829959. The reversal of 1978829957 is 7599288791.

It can be written as a sum of positive squares in 3 ways, for example, as 19351201 + 1959478756 = 4399^2 + 44266^2 .

It is not a de Polignac number, because 1978829957 - 2² = 1978829953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1978829893 and 1978829902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978829953) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5854358 + ... + 5854695.

It is an arithmetic number, because the mean of its divisors is an integer number (357126147).

Almost surely, 2^1978829957 is an apocalyptic number.

It is an amenable number.

1978829957 is a deficient number, since it is larger than the sum of its proper divisors (163926925).

1978829957 is a wasteful number, since it uses less digits than its factorization.

1978829957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11709079 (or 11709066 counting only the distinct ones).

The product of its digits is 22861440, while the sum is 65.

The square root of 1978829957 is about 44484.0415992072. The cubic root of 1978829957 is about 1255.4598415427.

The spelling of 1978829957 in words is "one billion, nine hundred seventy-eight million, eight hundred twenty-nine thousand, nine hundred fifty-seven".