81049690 has 16 divisors (see below), whose sum is σ = 146126592. Its totient is φ = 32367184.

The previous prime is 81049681. The next prime is 81049691. The reversal of 81049690 is 9694018.

It is a super-2 number, since 2×81049690² = 13138104498192200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81049691) 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 7 ways as a sum of consecutive naturals, for example, 207 + ... + 12733.

It is an arithmetic number, because the mean of its divisors is an integer number (9132912).

Almost surely, 2^81049690 is an apocalyptic number.

81049690 is a deficient number, since it is larger than the sum of its proper divisors (65076902).

81049690 is a wasteful number, since it uses less digits than its factorization.

81049690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13181.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 81049690 is about 9002.7601323150. The cubic root of 81049690 is about 432.7633287856.

The spelling of 81049690 in words is "eighty-one million, forty-nine thousand, six hundred ninety".