1971530816 has 14 divisors (see below), whose sum is σ = 3912256590. Its totient is φ = 985765376.

The previous prime is 1971530773. The next prime is 1971530819. The reversal of 1971530816 is 6180351791.

It can be written as a sum of positive squares in only one way, i.e., 1964262400 + 7268416 = 44320^2 + 2696^2 .

It is not an unprimeable number, because it can be changed into a prime (1971530819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15402521 + ... + 15402648.

Almost surely, 2^1971530816 is an apocalyptic number.

1971530816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1971530816 is a deficient number, since it is larger than the sum of its proper divisors (1940725774).

1971530816 is an equidigital number, since it uses as much as digits as its factorization.

1971530816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30805181 (or 30805171 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 1971530816 is about 44401.9235619359. The cubic root of 1971530816 is about 1253.9143038657.

The spelling of 1971530816 in words is "one billion, nine hundred seventy-one million, five hundred thirty thousand, eight hundred sixteen".