1891079947 has 2 divisors, whose sum is σ = 1891079948. Its totient is φ = 1891079946.

The previous prime is 1891079923. The next prime is 1891079969. The reversal of 1891079947 is 7499701981.

It is a strong prime.

It is an emirp because it is prime and its reverse (7499701981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1891079947 - 2¹⁹ = 1890555659 is a prime.

It is a super-3 number, since 3×1891079947³ (a number of 29 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1891079447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945539973 + 945539974.

It is an arithmetic number, because the mean of its divisors is an integer number (945539974).

Almost surely, 2^1891079947 is an apocalyptic number.

1891079947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891079947 is an equidigital number, since it uses as much as digits as its factorization.

1891079947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1143072, while the sum is 55.

The square root of 1891079947 is about 43486.5490353052. The cubic root of 1891079947 is about 1236.6210355638.

The spelling of 1891079947 in words is "one billion, eight hundred ninety-one million, seventy-nine thousand, nine hundred forty-seven".