65219821 has 2 divisors, whose sum is σ = 65219822. Its totient is φ = 65219820.

The previous prime is 65219813. The next prime is 65219849. The reversal of 65219821 is 12891256.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64979721 + 240100 = 8061^2 + 490^2 .

It is a cyclic number.

It is not a de Polignac number, because 65219821 - 2³ = 65219813 is a prime.

It is a super-3 number, since 3×65219821³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65219801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32609910 + 32609911.

It is an arithmetic number, because the mean of its divisors is an integer number (32609911).

Almost surely, 2^65219821 is an apocalyptic number.

It is an amenable number.

65219821 is a deficient number, since it is larger than the sum of its proper divisors (1).

65219821 is an equidigital number, since it uses as much as digits as its factorization.

65219821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 34.

The square root of 65219821 is about 8075.8789614506. The cubic root of 65219821 is about 402.5253171324.

The spelling of 65219821 in words is "sixty-five million, two hundred nineteen thousand, eight hundred twenty-one".