81278356 has 6 divisors (see below), whose sum is σ = 142237130. Its totient is φ = 40639176.

The previous prime is 81278347. The next prime is 81278383. The reversal of 81278356 is 65387218.

It can be written as a sum of positive squares in only one way, i.e., 44675856 + 36602500 = 6684^2 + 6050^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10159791 + ... + 10159798.

Almost surely, 2^81278356 is an apocalyptic number.

It is an amenable number.

81278356 is a deficient number, since it is larger than the sum of its proper divisors (60958774).

81278356 is a wasteful number, since it uses less digits than its factorization.

81278356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20319593 (or 20319591 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 81278356 is about 9015.4509593253. The cubic root of 81278356 is about 433.1699326072.

The spelling of 81278356 in words is "eighty-one million, two hundred seventy-eight thousand, three hundred fifty-six".