81724290701 has 2 divisors, whose sum is σ = 81724290702. Its totient is φ = 81724290700.

The previous prime is 81724290691. The next prime is 81724290727. The reversal of 81724290701 is 10709242718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45817830601 + 35906460100 = 214051^2 + 189490^2 .

It is a cyclic number.

It is not a de Polignac number, because 81724290701 - 2²² = 81720096397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81724290751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40862145350 + 40862145351.

It is an arithmetic number, because the mean of its divisors is an integer number (40862145351).

Almost surely, 2^81724290701 is an apocalyptic number.

It is an amenable number.

81724290701 is a deficient number, since it is larger than the sum of its proper divisors (1).

81724290701 is an equidigital number, since it uses as much as digits as its factorization.

81724290701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 41.

The spelling of 81724290701 in words is "eighty-one billion, seven hundred twenty-four million, two hundred ninety thousand, seven hundred one".