81355364 has 6 divisors (see below), whose sum is σ = 142371894. Its totient is φ = 40677680.

The previous prime is 81355363. The next prime is 81355381. The reversal of 81355364 is 46355318.

It can be written as a sum of positive squares in only one way, i.e., 57638464 + 23716900 = 7592^2 + 4870^2 .

It is not an unprimeable number, because it can be changed into a prime (81355363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10169417 + ... + 10169424.

It is an arithmetic number, because the mean of its divisors is an integer number (23728649).

Almost surely, 2^81355364 is an apocalyptic number.

It is an amenable number.

81355364 is a deficient number, since it is larger than the sum of its proper divisors (61016530).

81355364 is a wasteful number, since it uses less digits than its factorization.

81355364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20338845 (or 20338843 counting only the distinct ones).

The product of its digits is 43200, while the sum is 35.

The square root of 81355364 is about 9019.7208382521. The cubic root of 81355364 is about 433.3066931683.

The spelling of 81355364 in words is "eighty-one million, three hundred fifty-five thousand, three hundred sixty-four".