65815993 has 12 divisors (see below), whose sum is σ = 72335340. Its totient is φ = 59800832.

The previous prime is 65815991. The next prime is 65815999. The reversal of 65815993 is 39951856.

It can be written as a sum of positive squares in 6 ways, for example, as 11449 + 65804544 = 107^2 + 8112^2 .

It is not a de Polignac number, because 65815993 - 2¹ = 65815991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65815991) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4455 + ... + 12307.

It is an arithmetic number, because the mean of its divisors is an integer number (6027945).

Almost surely, 2^65815993 is an apocalyptic number.

It is an amenable number.

65815993 is a deficient number, since it is larger than the sum of its proper divisors (6519347).

65815993 is a wasteful number, since it uses less digits than its factorization.

65815993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7916 (or 7899 counting only the distinct ones).

The product of its digits is 291600, while the sum is 46.

The square root of 65815993 is about 8112.7056522470. The cubic root of 65815993 is about 403.7480886336.

The spelling of 65815993 in words is "sixty-five million, eight hundred fifteen thousand, nine hundred ninety-three".