971645566 has 4 divisors (see below), whose sum is σ = 1457468352. Its totient is φ = 485822782.

The previous prime is 971645537. The next prime is 971645573. The reversal of 971645566 is 665546179.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

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, 242911390 + ... + 242911393.

It is an arithmetic number, because the mean of its divisors is an integer number (364367088).

Almost surely, 2^971645566 is an apocalyptic number.

971645566 is a deficient number, since it is larger than the sum of its proper divisors (485822786).

971645566 is a wasteful number, since it uses less digits than its factorization.

971645566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485822785.

The product of its digits is 1360800, while the sum is 49.

The square root of 971645566 is about 31171.2297800392. The cubic root of 971645566 is about 990.4577572239.

The spelling of 971645566 in words is "nine hundred seventy-one million, six hundred forty-five thousand, five hundred sixty-six".