65121605 has 4 divisors (see below), whose sum is σ = 78145932. Its totient is φ = 52097280.

The previous prime is 65121599. The next prime is 65121631. The reversal of 65121605 is 50612156.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8300161 + 56821444 = 2881^2 + 7538^2 .

It is not a de Polignac number, because 65121605 - 2¹² = 65117509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6512156 + ... + 6512165.

It is an arithmetic number, because the mean of its divisors is an integer number (19536483).

Almost surely, 2^65121605 is an apocalyptic number.

It is an amenable number.

65121605 is a deficient number, since it is larger than the sum of its proper divisors (13024327).

65121605 is a wasteful number, since it uses less digits than its factorization.

65121605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13024326.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 65121605 is about 8069.7958462405. The cubic root of 65121605 is about 402.3231583008.

The spelling of 65121605 in words is "sixty-five million, one hundred twenty-one thousand, six hundred five".