81309246 has 16 divisors (see below), whose sum is σ = 171177600. Its totient is φ = 25676568.

The previous prime is 81309233. The next prime is 81309251. The reversal of 81309246 is 64290318.

It is a super-2 number, since 2×81309246² = 13222386970177032, which contains 22 as substring.

It is a congruent 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, 356506 + ... + 356733.

It is an arithmetic number, because the mean of its divisors is an integer number (10698600).

Almost surely, 2^81309246 is an apocalyptic number.

81309246 is an abundant number, since it is smaller than the sum of its proper divisors (89868354).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81309246 is a wasteful number, since it uses less digits than its factorization.

81309246 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713263.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 81309246 is about 9017.1639665695. The cubic root of 81309246 is about 433.2248013534.

The spelling of 81309246 in words is "eighty-one million, three hundred nine thousand, two hundred forty-six".