81355379 has 8 divisors (see below), whose sum is σ = 93446400. Its totient is φ = 69381576.

The previous prime is 81355363. The next prime is 81355381. The reversal of 81355379 is 97355318.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81355379 - 2⁴ = 81355363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81355349) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27809 + ... + 30594.

It is an arithmetic number, because the mean of its divisors is an integer number (11680800).

Almost surely, 2^81355379 is an apocalyptic number.

81355379 is a deficient number, since it is larger than the sum of its proper divisors (12091021).

81355379 is a wasteful number, since it uses less digits than its factorization.

81355379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58609.

The product of its digits is 113400, while the sum is 41.

The square root of 81355379 is about 9019.7216697634. The cubic root of 81355379 is about 433.3067197988.

The spelling of 81355379 in words is "eighty-one million, three hundred fifty-five thousand, three hundred seventy-nine".