3944951561 has 2 divisors, whose sum is σ = 3944951562. Its totient is φ = 3944951560.

The previous prime is 3944951501. The next prime is 3944951587. The reversal of 3944951561 is 1651594493.

It is a happy number.

3944951561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2263951561 + 1681000000 = 47581^2 + 41000^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3944951561 is a prime.

It is not a weakly prime, because it can be changed into another prime (3944951501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1972475780 + 1972475781.

It is an arithmetic number, because the mean of its divisors is an integer number (1972475781).

Almost surely, 2^3944951561 is an apocalyptic number.

It is an amenable number.

3944951561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3944951561 is an equidigital number, since it uses as much as digits as its factorization.

3944951561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583200, while the sum is 47.

The square root of 3944951561 is about 62808.8493844617. The cubic root of 3944951561 is about 1580.0853931575.

The spelling of 3944951561 in words is "three billion, nine hundred forty-four million, nine hundred fifty-one thousand, five hundred sixty-one".