81424378 has 12 divisors (see below), whose sum is σ = 142077402. Its totient is φ = 34896120.

The previous prime is 81424361. The next prime is 81424379. The reversal of 81424378 is 87342418.

It can be written as a sum of positive squares in only one way, i.e., 76685049 + 4739329 = 8757^2 + 2177^2 .

It is not an unprimeable number, because it can be changed into a prime (81424379) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 415333 + ... + 415528.

Almost surely, 2^81424378 is an apocalyptic number.

81424378 is a deficient number, since it is larger than the sum of its proper divisors (60653024).

81424378 is a wasteful number, since it uses less digits than its factorization.

81424378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830877 (or 830870 counting only the distinct ones).

The product of its digits is 43008, while the sum is 37.

The square root of 81424378 is about 9023.5457554112. The cubic root of 81424378 is about 433.4291836622.

The spelling of 81424378 in words is "eighty-one million, four hundred twenty-four thousand, three hundred seventy-eight".