65649999 has 4 divisors (see below), whose sum is σ = 87533336. Its totient is φ = 43766664.

The previous prime is 65649973. The next prime is 65650003. The reversal of 65649999 is 99994656.

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

It is not a de Polignac number, because 65649999 - 2¹⁵ = 65617231 is a prime.

It is a Duffinian number.

65649999 is a modest number, since divided by 9999 gives 6564 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65649919) 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, 10941664 + ... + 10941669.

It is an arithmetic number, because the mean of its divisors is an integer number (21883334).

Almost surely, 2^65649999 is an apocalyptic number.

65649999 is a deficient number, since it is larger than the sum of its proper divisors (21883337).

65649999 is a wasteful number, since it uses less digits than its factorization.

65649999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21883336.

The product of its digits is 4723920, while the sum is 57.

The square root of 65649999 is about 8102.4686978723. The cubic root of 65649999 is about 403.4083729121.

The spelling of 65649999 in words is "sixty-five million, six hundred forty-nine thousand, nine hundred ninety-nine".