1066020991 has 8 divisors (see below), whose sum is σ = 1229696640. Its totient is φ = 905192088.

The previous prime is 1066020961. The next prime is 1066021003. The reversal of 1066020991 is 1990206601.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1066020991 - 2¹⁹ = 1065496703 is a prime.

It is a super-2 number, since 2×1066020991² = 2272801506505244162, 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 (1066020941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 710881 + ... + 712378.

It is an arithmetic number, because the mean of its divisors is an integer number (153712080).

Almost surely, 2^1066020991 is an apocalyptic number.

1066020991 is a deficient number, since it is larger than the sum of its proper divisors (163675649).

1066020991 is a wasteful number, since it uses less digits than its factorization.

1066020991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1423373.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 1066020991 is about 32649.9768912629. The cubic root of 1066020991 is about 1021.5397068488.

The spelling of 1066020991 in words is "one billion, sixty-six million, twenty thousand, nine hundred ninety-one".