3815640985 has 16 divisors (see below), whose sum is σ = 4981825296. Its totient is φ = 2788651008.

The previous prime is 3815640977. The next prime is 3815641001. The reversal of 3815640985 is 5890465183.

It can be written as a sum of positive squares in 8 ways, for example, as 420947289 + 3394693696 = 20517^2 + 58264^2 .

It is not a de Polignac number, because 3815640985 - 2³ = 3815640977 is a prime.

It is a super-2 number, since 2×3815640985² = 29118232252823540450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 296284 + ... + 308893.

It is an arithmetic number, because the mean of its divisors is an integer number (311364081).

Almost surely, 2^3815640985 is an apocalyptic number.

It is an amenable number.

3815640985 is a deficient number, since it is larger than the sum of its proper divisors (1166184311).

3815640985 is a wasteful number, since it uses less digits than its factorization.

3815640985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605292.

The product of its (nonzero) digits is 1036800, while the sum is 49.

The square root of 3815640985 is about 61770.8748926223. The cubic root of 3815640985 is about 1562.6288385281.

The spelling of 3815640985 in words is "three billion, eight hundred fifteen million, six hundred forty thousand, nine hundred eighty-five".