665139970 has 16 divisors (see below), whose sum is σ = 1306093248. Its totient is φ = 241869040.

The previous prime is 665139899. The next prime is 665139971. The reversal of 665139970 is 79931566.

It is a super-2 number, since 2×665139970² = 884822359383201800, 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 665139970.

It is not an unprimeable number, because it can be changed into a prime (665139971) 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, 3023254 + ... + 3023473.

It is an arithmetic number, because the mean of its divisors is an integer number (81630828).

Almost surely, 2^665139970 is an apocalyptic number.

665139970 is a deficient number, since it is larger than the sum of its proper divisors (640953278).

665139970 is a wasteful number, since it uses less digits than its factorization.

665139970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6046745.

The product of its (nonzero) digits is 306180, while the sum is 46.

The square root of 665139970 is about 25790.3076755590. The cubic root of 665139970 is about 872.9131088600.

The spelling of 665139970 in words is "six hundred sixty-five million, one hundred thirty-nine thousand, nine hundred seventy".