1664673938 has 8 divisors (see below), whose sum is σ = 2528618880. Its totient is φ = 821800980.

The previous prime is 1664673937. The next prime is 1664673943. The reversal of 1664673938 is 8393764661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1664673938² = 5542278639712855688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1664673938.

It is not an unprimeable number, because it can be changed into a prime (1664673937) 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, 5267798 + ... + 5268113.

It is an arithmetic number, because the mean of its divisors is an integer number (316077360).

Almost surely, 2^1664673938 is an apocalyptic number.

1664673938 is a deficient number, since it is larger than the sum of its proper divisors (863944942).

1664673938 is a wasteful number, since it uses less digits than its factorization.

1664673938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10535992.

The product of its digits is 3919104, while the sum is 53.

The square root of 1664673938 is about 40800.4159047429. The cubic root of 1664673938 is about 1185.1583848306.

The spelling of 1664673938 in words is "one billion, six hundred sixty-four million, six hundred seventy-three thousand, nine hundred thirty-eight".