1606739521 has 2 divisors, whose sum is σ = 1606739522. Its totient is φ = 1606739520.

The previous prime is 1606739483. The next prime is 1606739527. The reversal of 1606739521 is 1259376061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1484946225 + 121793296 = 38535^2 + 11036^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1606739521 is a prime.

It is a super-2 number, since 2×1606739521² = 5163223776686618882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1606739527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 803369760 + 803369761.

It is an arithmetic number, because the mean of its divisors is an integer number (803369761).

Almost surely, 2^1606739521 is an apocalyptic number.

It is an amenable number.

1606739521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1606739521 is an equidigital number, since it uses as much as digits as its factorization.

1606739521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 68040, while the sum is 40.

The square root of 1606739521 is about 40084.1554856779. The cubic root of 1606739521 is about 1171.2470014772.

The spelling of 1606739521 in words is "one billion, six hundred six million, seven hundred thirty-nine thousand, five hundred twenty-one".