1971920506 has 4 divisors (see below), whose sum is σ = 2957880762. Its totient is φ = 985960252.

The previous prime is 1971920459. The next prime is 1971920527. The reversal of 1971920506 is 6050291791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6050291791 = 103 ⋅58740697.

It can be written as a sum of positive squares in only one way, i.e., 1588739881 + 383180625 = 39859^2 + 19575^2 .

It is an unprimeable number.

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, 492980125 + ... + 492980128.

Almost surely, 2^1971920506 is an apocalyptic number.

1971920506 is a deficient number, since it is larger than the sum of its proper divisors (985960256).

1971920506 is an equidigital number, since it uses as much as digits as its factorization.

1971920506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985960255.

The product of its (nonzero) digits is 34020, while the sum is 40.

The square root of 1971920506 is about 44406.3115559039. The cubic root of 1971920506 is about 1253.9969140673.

The spelling of 1971920506 in words is "one billion, nine hundred seventy-one million, nine hundred twenty thousand, five hundred six".