1966491819 has 6 divisors (see below), whose sum is σ = 2840488196. Its totient is φ = 1310994540.

The previous prime is 1966491817. The next prime is 1966491883. The reversal of 1966491819 is 9181946691.

1966491819 is a `hidden beast` number, since 19 + 66 + 491 + 81 + 9 = 666.

It is not a de Polignac number, because 1966491819 - 2¹ = 1966491817 is a prime.

It is a super-2 number, since 2×1966491819² = 7734180148387857522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1966491817) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 109249537 + ... + 109249554.

Almost surely, 2^1966491819 is an apocalyptic number.

1966491819 is a deficient number, since it is larger than the sum of its proper divisors (873996377).

1966491819 is a wasteful number, since it uses less digits than its factorization.

1966491819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218499097 (or 218499094 counting only the distinct ones).

The product of its digits is 839808, while the sum is 54.

The square root of 1966491819 is about 44345.1442550365. The cubic root of 1966491819 is about 1252.8451074312.

The spelling of 1966491819 in words is "one billion, nine hundred sixty-six million, four hundred ninety-one thousand, eight hundred nineteen".