81248501 has 2 divisors, whose sum is σ = 81248502. Its totient is φ = 81248500.

The previous prime is 81248473. The next prime is 81248507. The reversal of 81248501 is 10584218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79673476 + 1575025 = 8926^2 + 1255^2 .

It is a cyclic number.

It is not a de Polignac number, because 81248501 - 2²⁶ = 14139637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81248507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40624250 + 40624251.

It is an arithmetic number, because the mean of its divisors is an integer number (40624251).

Almost surely, 2^81248501 is an apocalyptic number.

It is an amenable number.

81248501 is a deficient number, since it is larger than the sum of its proper divisors (1).

81248501 is an equidigital number, since it uses as much as digits as its factorization.

81248501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 81248501 is about 9013.7950387170. The cubic root of 81248501 is about 433.1168890799.

The spelling of 81248501 in words is "eighty-one million, two hundred forty-eight thousand, five hundred one".