3961638406 has 16 divisors (see below), whose sum is σ = 6543270720. Its totient is φ = 1783914280.

The previous prime is 3961638403. The next prime is 3961638437. The reversal of 3961638406 is 6048361693.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3961638403) 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, 839116 + ... + 843823.

It is an arithmetic number, because the mean of its divisors is an integer number (408954420).

Almost surely, 2^3961638406 is an apocalyptic number.

3961638406 is a deficient number, since it is larger than the sum of its proper divisors (2581632314).

3961638406 is a wasteful number, since it uses less digits than its factorization.

3961638406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1683059.

The product of its (nonzero) digits is 559872, while the sum is 46.

The square root of 3961638406 is about 62941.5475342003. The cubic root of 3961638406 is about 1582.3101396011.

The spelling of 3961638406 in words is "three billion, nine hundred sixty-one million, six hundred thirty-eight thousand, four hundred six".