81197450 has 48 divisors (see below), whose sum is σ = 160465920. Its totient is φ = 30481920.

The previous prime is 81197449. The next prime is 81197453. The reversal of 81197450 is 5479118.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81197450.

It is not an unprimeable number, because it can be changed into a prime (81197453) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120314 + ... + 120986.

It is an arithmetic number, because the mean of its divisors is an integer number (3343040).

Almost surely, 2^81197450 is an apocalyptic number.

81197450 is a deficient number, since it is larger than the sum of its proper divisors (79268470).

81197450 is a wasteful number, since it uses less digits than its factorization.

81197450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831 (or 826 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 81197450 is about 9010.9627676514. The cubic root of 81197450 is about 433.0261563990.

The spelling of 81197450 in words is "eighty-one million, one hundred ninety-seven thousand, four hundred fifty".