81402378 has 16 divisors (see below), whose sum is σ = 163238880. Its totient is φ = 27061776.

The previous prime is 81402371. The next prime is 81402379. The reversal of 81402378 is 87320418.

It is not an unprimeable number, because it can be changed into a prime (81402371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15625 + ... + 20172.

It is an arithmetic number, because the mean of its divisors is an integer number (10202430).

Almost surely, 2^81402378 is an apocalyptic number.

81402378 is an abundant number, since it is smaller than the sum of its proper divisors (81836502).

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

81402378 is a wasteful number, since it uses less digits than its factorization.

81402378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36181.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 81402378 is about 9022.3266400635. The cubic root of 81402378 is about 433.3901441624.

The spelling of 81402378 in words is "eighty-one million, four hundred two thousand, three hundred seventy-eight".