65421378 has 64 divisors (see below), whose sum is σ = 159603840. Its totient is φ = 19699200.

The previous prime is 65421373. The next prime is 65421397. The reversal of 65421378 is 87312456.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

Its product of digits (40320) is a multiple of the sum of its prime factors (720).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65421373) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 142926 + ... + 143382.

It is an arithmetic number, because the mean of its divisors is an integer number (2493810).

Almost surely, 2^65421378 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65421378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79801920).

65421378 is an abundant number, since it is smaller than the sum of its proper divisors (94182462).

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

65421378 is a wasteful number, since it uses less digits than its factorization.

65421378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720 (or 714 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 65421378 is about 8088.3482862696. The cubic root of 65421378 is about 402.9395488799.

The spelling of 65421378 in words is "sixty-five million, four hundred twenty-one thousand, three hundred seventy-eight".