65621531889 has 15 divisors (see below), whose sum is σ = 98030670793. Its totient is φ = 43746150924.

The previous prime is 65621531867. The next prime is 65621531917. The reversal of 65621531889 is 98813512656.

The square root of 65621531889 is 256167.

It is a perfect power (a square), and thus also a powerful number.

65621531889 is a `hidden beast` number, since 6 + 5 + 6 + 21 + 531 + 8 + 89 = 666.

It is not a de Polignac number, because 65621531889 - 2⁷ = 65621531761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65621531839) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2291272 + ... + 2319734.

Almost surely, 2^65621531889 is an apocalyptic number.

65621531889 is the 256167-th square number.

65621531889 is the 128084-th centered octagonal number.

It is an amenable number.

65621531889 is a deficient number, since it is larger than the sum of its proper divisors (32409138904).

65621531889 is an frugal number, since it uses more digits than its factorization.

65621531889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56938 (or 28466 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 54.

The spelling of 65621531889 in words is "sixty-five billion, six hundred twenty-one million, five hundred thirty-one thousand, eight hundred eighty-nine".