1605266505 has 48 divisors (see below), whose sum is σ = 2890567680. Its totient is φ = 854644608.

The previous prime is 1605266501. The next prime is 1605266539. The reversal of 1605266505 is 5056625061.

It is a happy number.

It is not a de Polignac number, because 1605266505 - 2² = 1605266501 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1605266505.

It is not an unprimeable number, because it can be changed into a prime (1605266501) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1254456 + ... + 1255734.

It is an arithmetic number, because the mean of its divisors is an integer number (60220160).

Almost surely, 2^1605266505 is an apocalyptic number.

1605266505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1605266505 is a deficient number, since it is larger than the sum of its proper divisors (1285301175).

1605266505 is a wasteful number, since it uses less digits than its factorization.

1605266505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2332 (or 2320 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 1605266505 is about 40065.7772294511. Note that the first 3 decimals coincide. The cubic root of 1605266505 is about 1170.8889693579. Note that the first 3 decimals are identical.

The spelling of 1605266505 in words is "one billion, six hundred five million, two hundred sixty-six thousand, five hundred five".