81190951 has 4 divisors (see below), whose sum is σ = 81237312. Its totient is φ = 81144592.

The previous prime is 81190919. The next prime is 81190957. The reversal of 81190951 is 15909118.

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

It is a cyclic number.

It is not a de Polignac number, because 81190951 - 2⁵ = 81190919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81190957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20446 + ... + 24091.

It is an arithmetic number, because the mean of its divisors is an integer number (20309328).

Almost surely, 2^81190951 is an apocalyptic number.

81190951 is a deficient number, since it is larger than the sum of its proper divisors (46361).

81190951 is a wasteful number, since it uses less digits than its factorization.

81190951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46360.

The product of its (nonzero) digits is 3240, while the sum is 34.

The square root of 81190951 is about 9010.6021441411. The cubic root of 81190951 is about 433.0146030309.

The spelling of 81190951 in words is "eighty-one million, one hundred ninety thousand, nine hundred fifty-one".