1066367821 has 4 divisors (see below), whose sum is σ = 1066629600. Its totient is φ = 1066106044.

The previous prime is 1066367807. The next prime is 1066367899. The reversal of 1066367821 is 1287636601.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1287636601 = 7477 ⋅172213.

It is a cyclic number.

It is not a de Polignac number, because 1066367821 - 2⁷ = 1066367693 is a prime.

It is a super-2 number, since 2×1066367821² = 2274280659328576082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1066367801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124681 + ... + 132958.

It is an arithmetic number, because the mean of its divisors is an integer number (266657400).

Almost surely, 2^1066367821 is an apocalyptic number.

It is an amenable number.

1066367821 is a deficient number, since it is larger than the sum of its proper divisors (261779).

1066367821 is an equidigital number, since it uses as much as digits as its factorization.

1066367821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261778.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 1066367821 is about 32655.2877953939. The cubic root of 1066367821 is about 1021.6504808400.

The spelling of 1066367821 in words is "one billion, sixty-six million, three hundred sixty-seven thousand, eight hundred twenty-one".