1971326321 has 4 divisors (see below), whose sum is σ = 1977176292. Its totient is φ = 1965476352.

The previous prime is 1971326299. The next prime is 1971326347. The reversal of 1971326321 is 1236231791.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1434894400 + 536431921 = 37880^2 + 23161^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971326321 - 2¹⁴ = 1971309937 is a prime.

It is a super-2 number, since 2×1971326321² = 7772254927734790082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1971326221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2924480 + ... + 2925153.

It is an arithmetic number, because the mean of its divisors is an integer number (494294073).

Almost surely, 2^1971326321 is an apocalyptic number.

It is an amenable number.

1971326321 is a deficient number, since it is larger than the sum of its proper divisors (5849971).

1971326321 is an equidigital number, since it uses as much as digits as its factorization.

1971326321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5849970.

The product of its digits is 13608, while the sum is 35.

The square root of 1971326321 is about 44399.6207303621. The cubic root of 1971326321 is about 1253.8709487108.

The spelling of 1971326321 in words is "one billion, nine hundred seventy-one million, three hundred twenty-six thousand, three hundred twenty-one".