1909777957 has 2 divisors, whose sum is σ = 1909777958. Its totient is φ = 1909777956.

The previous prime is 1909777949. The next prime is 1909777979. The reversal of 1909777957 is 7597779091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1734639201 + 175138756 = 41649^2 + 13234^2 .

It is a cyclic number.

It is not a de Polignac number, because 1909777957 - 2³ = 1909777949 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1909777895 and 1909777904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1909777997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 954888978 + 954888979.

It is an arithmetic number, because the mean of its divisors is an integer number (954888979).

Almost surely, 2^1909777957 is an apocalyptic number.

It is an amenable number.

1909777957 is a deficient number, since it is larger than the sum of its proper divisors (1).

1909777957 is an equidigital number, since it uses as much as digits as its factorization.

1909777957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8751645, while the sum is 61.

The square root of 1909777957 is about 43701.0063614100. The cubic root of 1909777957 is about 1240.6833635739.

The spelling of 1909777957 in words is "one billion, nine hundred nine million, seven hundred seventy-seven thousand, nine hundred fifty-seven".