3964996561 has 2 divisors, whose sum is σ = 3964996562. Its totient is φ = 3964996560.

The previous prime is 3964996537. The next prime is 3964996571. The reversal of 3964996561 is 1656994693.

3964996561 is digitally balanced in base 2 and base 3, because in such bases 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., 3366900625 + 598095936 = 58025^2 + 24456^2 .

It is a cyclic number.

It is not a de Polignac number, because 3964996561 - 2¹³ = 3964988369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3964996496 and 3964996505.

It is not a weakly prime, because it can be changed into another prime (3964996501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1982498280 + 1982498281.

It is an arithmetic number, because the mean of its divisors is an integer number (1982498281).

Almost surely, 2^3964996561 is an apocalyptic number.

It is an amenable number.

3964996561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3964996561 is an equidigital number, since it uses as much as digits as its factorization.

3964996561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9447840, while the sum is 58.

The square root of 3964996561 is about 62968.2186583041. The cubic root of 3964996561 is about 1582.7571046752.

The spelling of 3964996561 in words is "three billion, nine hundred sixty-four million, nine hundred ninety-six thousand, five hundred sixty-one".