1966521331 has 2 divisors, whose sum is σ = 1966521332. Its totient is φ = 1966521330.

The previous prime is 1966521329. The next prime is 1966521343. The reversal of 1966521331 is 1331256691.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (1331256691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1966521331 - 2¹ = 1966521329 is a prime.

It is a super-2 number, since 2×1966521331² = 7734412290556023122, which contains 22 as substring.

Together with 1966521329, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1966521311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 983260665 + 983260666.

It is an arithmetic number, because the mean of its divisors is an integer number (983260666).

Almost surely, 2^1966521331 is an apocalyptic number.

1966521331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1966521331 is an equidigital number, since it uses as much as digits as its factorization.

1966521331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29160, while the sum is 37.

The square root of 1966521331 is about 44345.4770072439. The cubic root of 1966521331 is about 1252.8513747308.

The spelling of 1966521331 in words is "one billion, nine hundred sixty-six million, five hundred twenty-one thousand, three hundred thirty-one".