65821556478 has 24 divisors (see below), whose sum is σ = 132196913928. Its totient is φ = 21848603728.

The previous prime is 65821556477. The next prime is 65821556551. The reversal of 65821556478 is 87465512856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65821556477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 246700 + ... + 438752.

It is an arithmetic number, because the mean of its divisors is an integer number (5508204747).

Almost surely, 2^65821556478 is an apocalyptic number.

65821556478 is an abundant number, since it is smaller than the sum of its proper divisors (66375357450).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65821556478 is a wasteful number, since it uses less digits than its factorization.

65821556478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192536 (or 192297 counting only the distinct ones).

The product of its digits is 16128000, while the sum is 57.

The spelling of 65821556478 in words is "sixty-five billion, eight hundred twenty-one million, five hundred fifty-six thousand, four hundred seventy-eight".