81620107 has 2 divisors, whose sum is σ = 81620108. Its totient is φ = 81620106.

The previous prime is 81620101. The next prime is 81620141. The reversal of 81620107 is 70102618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81620107 - 2¹⁵ = 81587339 is a prime.

It is not a weakly prime, because it can be changed into another prime (81620101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40810053 + 40810054.

It is an arithmetic number, because the mean of its divisors is an integer number (40810054).

Almost surely, 2^81620107 is an apocalyptic number.

81620107 is a deficient number, since it is larger than the sum of its proper divisors (1).

81620107 is an equidigital number, since it uses as much as digits as its factorization.

81620107 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 81620107 is about 9034.3847051141. The cubic root of 81620107 is about 433.7762000302.

The spelling of 81620107 in words is "eighty-one million, six hundred twenty thousand, one hundred seven".