81081379 has 4 divisors (see below), whose sum is σ = 85348840. Its totient is φ = 76813920.

The previous prime is 81081373. The next prime is 81081389. The reversal of 81081379 is 97318018.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81081379 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (81081373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2133702 + ... + 2133739.

It is an arithmetic number, because the mean of its divisors is an integer number (21337210).

Almost surely, 2^81081379 is an apocalyptic number.

81081379 is a deficient number, since it is larger than the sum of its proper divisors (4267461).

81081379 is a wasteful number, since it uses less digits than its factorization.

81081379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4267460.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 81081379 is about 9004.5199205732. The cubic root of 81081379 is about 432.8197223807.

The spelling of 81081379 in words is "eighty-one million, eighty-one thousand, three hundred seventy-nine".