1666690018 has 24 divisors (see below), whose sum is σ = 2945030400. Its totient is φ = 705250728.

The previous prime is 1666689989. The next prime is 1666690033. The reversal of 1666690018 is 8100966661.

It is a happy number.

It is a super-2 number, since 2×1666690018² = 5555711232201680648, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 99898 + ... + 115381.

It is an arithmetic number, because the mean of its divisors is an integer number (122709600).

Almost surely, 2^1666690018 is an apocalyptic number.

1666690018 is a deficient number, since it is larger than the sum of its proper divisors (1278340382).

1666690018 is a wasteful number, since it uses less digits than its factorization.

1666690018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215374 (or 215367 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 1666690018 is about 40825.1150396420. The cubic root of 1666690018 is about 1185.6366386842.

The spelling of 1666690018 in words is "one billion, six hundred sixty-six million, six hundred ninety thousand, eighteen".