65623821 has 16 divisors (see below), whose sum is σ = 90359808. Its totient is φ = 42336000.

The previous prime is 65623813. The next prime is 65623823. The reversal of 65623821 is 12832656.

It is not a de Polignac number, because 65623821 - 2³ = 65623813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65623823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13521 + ... + 17721.

It is an arithmetic number, because the mean of its divisors is an integer number (5647488).

Almost surely, 2^65623821 is an apocalyptic number.

It is an amenable number.

65623821 is a deficient number, since it is larger than the sum of its proper divisors (24735987).

65623821 is a wasteful number, since it uses less digits than its factorization.

65623821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4372.

The product of its digits is 17280, while the sum is 33.

The square root of 65623821 is about 8100.8531032231. The cubic root of 65623821 is about 403.3547459585.

The spelling of 65623821 in words is "sixty-five million, six hundred twenty-three thousand, eight hundred twenty-one".