265380321978 has 64 divisors (see below), whose sum is σ = 597883852800. Its totient is φ = 87240207600.

The previous prime is 265380321929. The next prime is 265380322003. The reversal of 265380321978 is 879123083562.

265380321978 is a `hidden beast` number, since 2 + 6 + 538 + 0 + 32 + 1 + 9 + 78 = 666.

265380321978 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 3731653 + ... + 3802103.

It is an arithmetic number, because the mean of its divisors is an integer number (9341935200).

Almost surely, 2^265380321978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 265380321978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298941926400).

265380321978 is an abundant number, since it is smaller than the sum of its proper divisors (332503530822).

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

265380321978 is a wasteful number, since it uses less digits than its factorization.

265380321978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71424 (or 71418 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 265380321978 in words is "two hundred sixty-five billion, three hundred eighty million, three hundred twenty-one thousand, nine hundred seventy-eight".