1947113557 has 2 divisors, whose sum is σ = 1947113558. Its totient is φ = 1947113556.

The previous prime is 1947113549. The next prime is 1947113569. The reversal of 1947113557 is 7553117491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1943575396 + 3538161 = 44086^2 + 1881^2 .

It is an emirp because it is prime and its reverse (7553117491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1947113557 - 2³ = 1947113549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1947113527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 973556778 + 973556779.

It is an arithmetic number, because the mean of its divisors is an integer number (973556779).

Almost surely, 2^1947113557 is an apocalyptic number.

It is an amenable number.

1947113557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1947113557 is an equidigital number, since it uses as much as digits as its factorization.

1947113557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 132300, while the sum is 43.

The square root of 1947113557 is about 44126.1096970943. The cubic root of 1947113557 is about 1248.7162408480.

The spelling of 1947113557 in words is "one billion, nine hundred forty-seven million, one hundred thirteen thousand, five hundred fifty-seven".