3921516649 has 2 divisors, whose sum is σ = 3921516650. Its totient is φ = 3921516648.

The previous prime is 3921516589. The next prime is 3921516671. The reversal of 3921516649 is 9466151293.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2013137424 + 1908379225 = 44868^2 + 43685^2 .

It is a cyclic number.

It is not a de Polignac number, because 3921516649 - 2²⁵ = 3887962217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3921516599 and 3921516608.

It is not a weakly prime, because it can be changed into another prime (3921516689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1960758324 + 1960758325.

It is an arithmetic number, because the mean of its divisors is an integer number (1960758325).

Almost surely, 2^3921516649 is an apocalyptic number.

It is an amenable number.

3921516649 is a deficient number, since it is larger than the sum of its proper divisors (1).

3921516649 is an equidigital number, since it uses as much as digits as its factorization.

3921516649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 349920, while the sum is 46.

The square root of 3921516649 is about 62622.0140924899. The cubic root of 3921516649 is about 1576.9503543446.

The spelling of 3921516649 in words is "three billion, nine hundred twenty-one million, five hundred sixteen thousand, six hundred forty-nine".