1605252101 has 4 divisors (see below), whose sum is σ = 1605626400. Its totient is φ = 1604877804.

The previous prime is 1605252083. The next prime is 1605252139. The reversal of 1605252101 is 1012525061.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1605252101 - 2¹⁴ = 1605235717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1605252151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180641 + ... + 189318.

It is an arithmetic number, because the mean of its divisors is an integer number (401406600).

Almost surely, 2^1605252101 is an apocalyptic number.

It is an amenable number.

1605252101 is a deficient number, since it is larger than the sum of its proper divisors (374299).

1605252101 is an equidigital number, since it uses as much as digits as its factorization.

1605252101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374298.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 1605252101 is about 40065.5974746415. The cubic root of 1605252101 is about 1170.8854672322.

Adding to 1605252101 its reverse (1012525061), we get a palindrome (2617777162).

The spelling of 1605252101 in words is "one billion, six hundred five million, two hundred fifty-two thousand, one hundred one".