81661703 has 2 divisors, whose sum is σ = 81661704. Its totient is φ = 81661702.

The previous prime is 81661673. The next prime is 81661721. The reversal of 81661703 is 30716618.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81661703 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81661703.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81661733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40830851 + 40830852.

It is an arithmetic number, because the mean of its divisors is an integer number (40830852).

Almost surely, 2^81661703 is an apocalyptic number.

81661703 is a deficient number, since it is larger than the sum of its proper divisors (1).

81661703 is an equidigital number, since it uses as much as digits as its factorization.

81661703 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 81661703 is about 9036.6865055727. The cubic root of 81661703 is about 433.8498758731.

The spelling of 81661703 in words is "eighty-one million, six hundred sixty-one thousand, seven hundred three".