1665964016 has 20 divisors (see below), whose sum is σ = 3228452592. Its totient is φ = 832814976.

The previous prime is 1665964009. The next prime is 1665964049. The reversal of 1665964016 is 6104695661.

It is a super-2 number, since 2×1665964016² = 5550872205213696512, which contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125405 + ... + 138051.

Almost surely, 2^1665964016 is an apocalyptic number.

1665964016 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1665964016 is a deficient number, since it is larger than the sum of its proper divisors (1562488576).

1665964016 is a wasteful number, since it uses less digits than its factorization.

1665964016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20888 (or 20882 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 1665964016 is about 40816.2224611734. Note that the first 3 decimals coincide. The cubic root of 1665964016 is about 1185.4644611797.

The spelling of 1665964016 in words is "one billion, six hundred sixty-five million, nine hundred sixty-four thousand, sixteen".