1966499785 has 4 divisors (see below), whose sum is σ = 2359799748. Its totient is φ = 1573199824.

The previous prime is 1966499783. The next prime is 1966499869. The reversal of 1966499785 is 5879946691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5879946691 = 311 ⋅18906581.

It can be written as a sum of positive squares in 2 ways, for example, as 368179344 + 1598320441 = 19188^2 + 39979^2 .

It is a cyclic number.

It is not a de Polignac number, because 1966499785 - 2¹ = 1966499783 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1966499783) 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, 196649974 + ... + 196649983.

It is an arithmetic number, because the mean of its divisors is an integer number (589949937).

Almost surely, 2^1966499785 is an apocalyptic number.

It is an amenable number.

1966499785 is a deficient number, since it is larger than the sum of its proper divisors (393299963).

1966499785 is an equidigital number, since it uses as much as digits as its factorization.

1966499785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393299962.

The product of its digits is 29393280, while the sum is 64.

The square root of 1966499785 is about 44345.2340731222. The cubic root of 1966499785 is about 1252.8467991326.

The spelling of 1966499785 in words is "one billion, nine hundred sixty-six million, four hundred ninety-nine thousand, seven hundred eighty-five".