3906015621 has 4 divisors (see below), whose sum is σ = 5208020832. Its totient is φ = 2604010412.

The previous prime is 3906015601. The next prime is 3906015629. The reversal of 3906015621 is 1265106093.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1265106093 = 3 ⋅421702031.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3906015621 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3906015629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 651002601 + ... + 651002606.

It is an arithmetic number, because the mean of its divisors is an integer number (1302005208).

Almost surely, 2^3906015621 is an apocalyptic number.

It is an amenable number.

3906015621 is a deficient number, since it is larger than the sum of its proper divisors (1302005211).

3906015621 is a wasteful number, since it uses less digits than its factorization.

3906015621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1302005210.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 3906015621 is about 62498.1249398732. The cubic root of 3906015621 is about 1574.8698131748.

The spelling of 3906015621 in words is "three billion, nine hundred six million, fifteen thousand, six hundred twenty-one".