81078464 has 14 divisors (see below), whose sum is σ = 160890204. Its totient is φ = 40539200.

The previous prime is 81078463. The next prime is 81078479. The reversal of 81078464 is 46487018.

It is not an unprimeable number, because it can be changed into a prime (81078463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633362 + ... + 633489.

Almost surely, 2^81078464 is an apocalyptic number.

It is an amenable number.

81078464 is a deficient number, since it is larger than the sum of its proper divisors (79811740).

81078464 is a wasteful number, since it uses less digits than its factorization.

81078464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1266863 (or 1266853 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 38.

The square root of 81078464 is about 9004.3580559638. The cubic root of 81078464 is about 432.8145354742.

The spelling of 81078464 in words is "eighty-one million, seventy-eight thousand, four hundred sixty-four".