1011999971 has 2 divisors, whose sum is σ = 1011999972. Its totient is φ = 1011999970.

The previous prime is 1011999941. The next prime is 1012000009. The reversal of 1011999971 is 1799991101.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1011999971 - 2¹⁰ = 1011998947 is a prime.

It is not a weakly prime, because it can be changed into another prime (1011999941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505999985 + 505999986.

It is an arithmetic number, because the mean of its divisors is an integer number (505999986).

Almost surely, 2^1011999971 is an apocalyptic number.

1011999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011999971 is an equidigital number, since it uses as much as digits as its factorization.

1011999971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45927, while the sum is 47.

The square root of 1011999971 is about 31811.9469853701. The cubic root of 1011999971 is about 1003.9840962307.

The spelling of 1011999971 in words is "one billion, eleven million, nine hundred ninety-nine thousand, nine hundred seventy-one".