65672821 has 2 divisors, whose sum is σ = 65672822. Its totient is φ = 65672820.

The previous prime is 65672753. The next prime is 65672839. The reversal of 65672821 is 12827656.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61308900 + 4363921 = 7830^2 + 2089^2 .

It is a cyclic number.

It is not a de Polignac number, because 65672821 - 2¹³ = 65664629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65672851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32836410 + 32836411.

It is an arithmetic number, because the mean of its divisors is an integer number (32836411).

Almost surely, 2^65672821 is an apocalyptic number.

It is an amenable number.

65672821 is a deficient number, since it is larger than the sum of its proper divisors (1).

65672821 is an equidigital number, since it uses as much as digits as its factorization.

65672821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 37.

The square root of 65672821 is about 8103.8769117010. The cubic root of 65672821 is about 403.4551133000.

The spelling of 65672821 in words is "sixty-five million, six hundred seventy-two thousand, eight hundred twenty-one".