1981906147 has 16 divisors (see below), whose sum is σ = 2194827712. Its totient is φ = 1777749120.

The previous prime is 1981906123. The next prime is 1981906151. The reversal of 1981906147 is 7416091891.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1981906147 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1981906097 and 1981906106.

It is not an unprimeable number, because it can be changed into a prime (1981906117) 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 in 15 ways as a sum of consecutive naturals, for example, 462997 + ... + 467257.

It is an arithmetic number, because the mean of its divisors is an integer number (137176732).

Almost surely, 2^1981906147 is an apocalyptic number.

1981906147 is a deficient number, since it is larger than the sum of its proper divisors (212921565).

1981906147 is a wasteful number, since it uses less digits than its factorization.

1981906147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5278.

The product of its (nonzero) digits is 108864, while the sum is 46.

The square root of 1981906147 is about 44518.6045041845. The cubic root of 1981906147 is about 1256.1100630675.

The spelling of 1981906147 in words is "one billion, nine hundred eighty-one million, nine hundred six thousand, one hundred forty-seven".