82621809 has 8 divisors (see below), whose sum is σ = 122402720. Its totient is φ = 55081188.

The previous prime is 82621807. The next prime is 82621811. The reversal of 82621809 is 90812628.

It is an interprime number because it is at equal distance from previous prime (82621807) and next prime (82621811).

It is not a de Polignac number, because 82621809 - 2¹ = 82621807 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (82621807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1530007 + ... + 1530060.

It is an arithmetic number, because the mean of its divisors is an integer number (15300340).

Almost surely, 2^82621809 is an apocalyptic number.

It is an amenable number.

82621809 is a deficient number, since it is larger than the sum of its proper divisors (39780911).

82621809 is a wasteful number, since it uses less digits than its factorization.

82621809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3060076 (or 3060070 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 82621809 is about 9089.6539538092. The cubic root of 82621809 is about 435.5435298546.

The spelling of 82621809 in words is "eighty-two million, six hundred twenty-one thousand, eight hundred nine".