1605026261 has 2 divisors, whose sum is σ = 1605026262. Its totient is φ = 1605026260.

The previous prime is 1605026243. The next prime is 1605026309. The reversal of 1605026261 is 1626205061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 960628036 + 644398225 = 30994^2 + 25385^2 .

It is a cyclic number.

It is not a de Polignac number, because 1605026261 - 2¹⁴ = 1605009877 is a prime.

It is a super-2 number, since 2×1605026261² = 5152218596999280242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1605026161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802513130 + 802513131.

It is an arithmetic number, because the mean of its divisors is an integer number (802513131).

Almost surely, 2^1605026261 is an apocalyptic number.

It is an amenable number.

1605026261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1605026261 is an equidigital number, since it uses as much as digits as its factorization.

1605026261 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 1605026261 is about 40062.7789974685. The cubic root of 1605026261 is about 1170.8305547410.

The spelling of 1605026261 in words is "one billion, six hundred five million, twenty-six thousand, two hundred sixty-one".