81198701 has 2 divisors, whose sum is σ = 81198702. Its totient is φ = 81198700.

The previous prime is 81198697. The next prime is 81198709. The reversal of 81198701 is 10789118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79673476 + 1525225 = 8926^2 + 1235^2 .

It is a cyclic number.

It is not a de Polignac number, because 81198701 - 2² = 81198697 is a prime.

It is equal to p_4735448 and since 81198701 and 4735448 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81198709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40599350 + 40599351.

It is an arithmetic number, because the mean of its divisors is an integer number (40599351).

Almost surely, 2^81198701 is an apocalyptic number.

It is an amenable number.

81198701 is a deficient number, since it is larger than the sum of its proper divisors (1).

81198701 is an equidigital number, since it uses as much as digits as its factorization.

81198701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 81198701 is about 9011.0321828301. The cubic root of 81198701 is about 433.0283802494.

The spelling of 81198701 in words is "eighty-one million, one hundred ninety-eight thousand, seven hundred one".