81649061 has 8 divisors (see below), whose sum is σ = 92557920. Its totient is φ = 71401392.

The previous prime is 81649021. The next prime is 81649069. The reversal of 81649061 is 16094618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81649061 - 2²² = 77454757 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81649069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165035 + ... + 165528.

It is an arithmetic number, because the mean of its divisors is an integer number (11569740).

Almost surely, 2^81649061 is an apocalyptic number.

It is an amenable number.

81649061 is a deficient number, since it is larger than the sum of its proper divisors (10908859).

81649061 is a wasteful number, since it uses less digits than its factorization.

81649061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330595.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 81649061 is about 9035.9869964493. The cubic root of 81649061 is about 433.8274867034.

The spelling of 81649061 in words is "eighty-one million, six hundred forty-nine thousand, sixty-one".