3865640988 has 24 divisors (see below), whose sum is σ = 9839813760. Its totient is φ = 1171406320.

The previous prime is 3865640983. The next prime is 3865641011. The reversal of 3865640988 is 8890465683.

It is a super-2 number, since 2×3865640988² = 29886360496211232288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3865640983) 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, 14642448 + ... + 14642711.

It is an arithmetic number, because the mean of its divisors is an integer number (409992240).

Almost surely, 2^3865640988 is an apocalyptic number.

It is an amenable number.

3865640988 is an abundant number, since it is smaller than the sum of its proper divisors (5974172772).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3865640988 is a wasteful number, since it uses less digits than its factorization.

3865640988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29285177 (or 29285175 counting only the distinct ones).

The product of its (nonzero) digits is 9953280, while the sum is 57.

The square root of 3865640988 is about 62174.2791514305. The cubic root of 3865640988 is about 1569.4247812300.

The spelling of 3865640988 in words is "three billion, eight hundred sixty-five million, six hundred forty thousand, nine hundred eighty-eight".