1971009778 has 8 divisors (see below), whose sum is σ = 2957433840. Its totient is φ = 985198500.

The previous prime is 1971009773. The next prime is 1971009779. The reversal of 1971009778 is 8779001791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1971009773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145068 + ... + 158071.

It is an arithmetic number, because the mean of its divisors is an integer number (369679230).

Almost surely, 2^1971009778 is an apocalyptic number.

1971009778 is a deficient number, since it is larger than the sum of its proper divisors (986424062).

1971009778 is a wasteful number, since it uses less digits than its factorization.

1971009778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306392.

The product of its (nonzero) digits is 222264, while the sum is 49.

The square root of 1971009778 is about 44396.0558833777. The cubic root of 1971009778 is about 1253.8038322533.

The spelling of 1971009778 in words is "one billion, nine hundred seventy-one million, nine thousand, seven hundred seventy-eight".