65603821 has 2 divisors, whose sum is σ = 65603822. Its totient is φ = 65603820.

The previous prime is 65603809. The next prime is 65603831. The reversal of 65603821 is 12830656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64979721 + 624100 = 8061^2 + 790^2 .

It is a cyclic number.

It is not a de Polignac number, because 65603821 - 2¹⁵ = 65571053 is a prime.

It is a super-2 number, since 2×65603821² = 8607722659600082, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65603801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32801910 + 32801911.

It is an arithmetic number, because the mean of its divisors is an integer number (32801911).

Almost surely, 2^65603821 is an apocalyptic number.

It is an amenable number.

65603821 is a deficient number, since it is larger than the sum of its proper divisors (1).

65603821 is an equidigital number, since it uses as much as digits as its factorization.

65603821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 65603821 is about 8099.6185712662. The cubic root of 65603821 is about 403.3137653386.

The spelling of 65603821 in words is "sixty-five million, six hundred three thousand, eight hundred twenty-one".