991087066 has 16 divisors (see below), whose sum is σ = 1565002944. Its totient is φ = 469801024.

The previous prime is 991087061. The next prime is 991087067. The reversal of 991087066 is 660780199.

It is a super-3 number, since 3×991087066³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is not an unprimeable number, because it can be changed into a prime (991087061) 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, 90136 + ... + 100531.

It is an arithmetic number, because the mean of its divisors is an integer number (97812684).

Almost surely, 2^991087066 is an apocalyptic number.

991087066 is a deficient number, since it is larger than the sum of its proper divisors (573915878).

991087066 is a wasteful number, since it uses less digits than its factorization.

991087066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190805.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 991087066 is about 31481.5353183418. The cubic root of 991087066 is about 997.0201513217.

The spelling of 991087066 in words is "nine hundred ninety-one million, eighty-seven thousand, sixty-six".