1640600561 has 2 divisors, whose sum is σ = 1640600562. Its totient is φ = 1640600560.

The previous prime is 1640600497. The next prime is 1640600567. The reversal of 1640600561 is 1650060461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1448944225 + 191656336 = 38065^2 + 13844^2 .

It is a cyclic number.

It is not a de Polignac number, because 1640600561 - 2⁶ = 1640600497 is a prime.

It is not a weakly prime, because it can be changed into another prime (1640600567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820300280 + 820300281.

It is an arithmetic number, because the mean of its divisors is an integer number (820300281).

Almost surely, 2^1640600561 is an apocalyptic number.

It is an amenable number.

1640600561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640600561 is an equidigital number, since it uses as much as digits as its factorization.

1640600561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 1640600561 is about 40504.3276823601. The cubic root of 1640600561 is about 1179.4176387594.

The spelling of 1640600561 in words is "one billion, six hundred forty million, six hundred thousand, five hundred sixty-one".