65897321821 has 4 divisors (see below), whose sum is σ = 66400354944. Its totient is φ = 65394288700.

The previous prime is 65897321807. The next prime is 65897321909. The reversal of 65897321821 is 12812379856.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65897321821 - 2¹¹ = 65897319773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65897321921) 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, 251516365 + ... + 251516626.

It is an arithmetic number, because the mean of its divisors is an integer number (16600088736).

Almost surely, 2^65897321821 is an apocalyptic number.

It is an amenable number.

65897321821 is a deficient number, since it is larger than the sum of its proper divisors (503033123).

65897321821 is a wasteful number, since it uses less digits than its factorization.

65897321821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503033122.

The product of its digits is 1451520, while the sum is 52.

The spelling of 65897321821 in words is "sixty-five billion, eight hundred ninety-seven million, three hundred twenty-one thousand, eight hundred twenty-one".