1664870397 has 8 divisors (see below), whose sum is σ = 2261710944. Its totient is φ = 1088971728.

The previous prime is 1664870353. The next prime is 1664870413. The reversal of 1664870397 is 7930784661.

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

It is not a de Polignac number, because 1664870397 - 2¹⁰ = 1664869373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664870327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5235283 + ... + 5235600.

It is an arithmetic number, because the mean of its divisors is an integer number (282713868).

Almost surely, 2^1664870397 is an apocalyptic number.

It is an amenable number.

1664870397 is a deficient number, since it is larger than the sum of its proper divisors (596840547).

1664870397 is a wasteful number, since it uses less digits than its factorization.

1664870397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10470939.

The product of its (nonzero) digits is 1524096, while the sum is 51.

The square root of 1664870397 is about 40802.8233949564. The cubic root of 1664870397 is about 1185.2050057467.

The spelling of 1664870397 in words is "one billion, six hundred sixty-four million, eight hundred seventy thousand, three hundred ninety-seven".