1972991786 has 8 divisors (see below), whose sum is σ = 2982079584. Its totient is φ = 978965260.

The previous prime is 1972991731. The next prime is 1972991789. The reversal of 1972991786 is 6871992791.

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 (1972991789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3764990 + ... + 3765513.

It is an arithmetic number, because the mean of its divisors is an integer number (372759948).

Almost surely, 2^1972991786 is an apocalyptic number.

1972991786 is a deficient number, since it is larger than the sum of its proper divisors (1009087798).

1972991786 is a wasteful number, since it uses less digits than its factorization.

1972991786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7530636.

The product of its digits is 3429216, while the sum is 59.

The square root of 1972991786 is about 44418.3721673814. The cubic root of 1972991786 is about 1254.2239581446.

The spelling of 1972991786 in words is "one billion, nine hundred seventy-two million, nine hundred ninety-one thousand, seven hundred eighty-six".