81950905 has 8 divisors (see below), whose sum is σ = 100628352. Its totient is φ = 64035888.

The previous prime is 81950873. The next prime is 81950927. The reversal of 81950905 is 50905918.

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 81950905 - 2⁵ = 81950873 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190369 + ... + 190798.

It is an arithmetic number, because the mean of its divisors is an integer number (12578544).

Almost surely, 2^81950905 is an apocalyptic number.

It is an amenable number.

81950905 is a deficient number, since it is larger than the sum of its proper divisors (18677447).

81950905 is a wasteful number, since it uses less digits than its factorization.

81950905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381215.

The product of its (nonzero) digits is 16200, while the sum is 37.

The square root of 81950905 is about 9052.6739143747. The cubic root of 81950905 is about 434.3614270727.

The spelling of 81950905 in words is "eighty-one million, nine hundred fifty thousand, nine hundred five".