65421623520 has 144 divisors (see below), whose sum is σ = 243546921072. Its totient is φ = 15859783680.

The previous prime is 65421623513. The next prime is 65421623569. The reversal of 65421623520 is 2532612456.

65421623520 is a `hidden beast` number, since 6 + 5 + 4 + 2 + 1 + 623 + 5 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2049237 + ... + 2080916.

It is an arithmetic number, because the mean of its divisors is an integer number (1691298063).

Almost surely, 2^65421623520 is an apocalyptic number.

65421623520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

65421623520 is an abundant number, since it is smaller than the sum of its proper divisors (178125297552).

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

65421623520 is a wasteful number, since it uses less digits than its factorization.

65421623520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4130185 (or 4130174 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The spelling of 65421623520 in words is "sixty-five billion, four hundred twenty-one million, six hundred twenty-three thousand, five hundred twenty".