86193781 has 2 divisors, whose sum is σ = 86193782. Its totient is φ = 86193780.

The previous prime is 86193773. The next prime is 86193803. The reversal of 86193781 is 18739168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85655025 + 538756 = 9255^2 + 734^2 .

It is a cyclic number.

It is not a de Polignac number, because 86193781 - 2³ = 86193773 is a prime.

It is a super-2 number, since 2×86193781² = 14858735766151922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86193721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43096890 + 43096891.

It is an arithmetic number, because the mean of its divisors is an integer number (43096891).

Almost surely, 2^86193781 is an apocalyptic number.

It is an amenable number.

86193781 is a deficient number, since it is larger than the sum of its proper divisors (1).

86193781 is an equidigital number, since it uses as much as digits as its factorization.

86193781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 43.

The square root of 86193781 is about 9284.0605879109. The cubic root of 86193781 is about 441.7317786684.

The spelling of 86193781 in words is "eighty-six million, one hundred ninety-three thousand, seven hundred eighty-one".