1605162761 has 2 divisors, whose sum is σ = 1605162762. Its totient is φ = 1605162760.

The previous prime is 1605162743. The next prime is 1605162787. The reversal of 1605162761 is 1672615061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1289887225 + 315275536 = 35915^2 + 17756^2 .

It is a cyclic number.

It is not a de Polignac number, because 1605162761 - 2¹⁴ = 1605146377 is a prime.

It is a super-2 number, since 2×1605162761² = 5153094978602286242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1605102761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802581380 + 802581381.

It is an arithmetic number, because the mean of its divisors is an integer number (802581381).

Almost surely, 2^1605162761 is an apocalyptic number.

It is an amenable number.

1605162761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1605162761 is an equidigital number, since it uses as much as digits as its factorization.

1605162761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 1605162761 is about 40064.4825375294. The cubic root of 1605162761 is about 1170.8637450266.

The spelling of 1605162761 in words is "one billion, six hundred five million, one hundred sixty-two thousand, seven hundred sixty-one".