1606405121 has 2 divisors, whose sum is σ = 1606405122. Its totient is φ = 1606405120.

The previous prime is 1606405117. The next prime is 1606405139. The reversal of 1606405121 is 1215046061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1566576400 + 39828721 = 39580^2 + 6311^2 .

It is a cyclic number.

It is not a de Polignac number, because 1606405121 - 2² = 1606405117 is a prime.

It is not a weakly prime, because it can be changed into another prime (1606405181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 803202560 + 803202561.

It is an arithmetic number, because the mean of its divisors is an integer number (803202561).

Almost surely, 2^1606405121 is an apocalyptic number.

It is an amenable number.

1606405121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1606405121 is an equidigital number, since it uses as much as digits as its factorization.

1606405121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 1606405121 is about 40079.9840444080. The cubic root of 1606405121 is about 1171.1657412258.

The spelling of 1606405121 in words is "one billion, six hundred six million, four hundred five thousand, one hundred twenty-one".