81303511 has 2 divisors, whose sum is σ = 81303512. Its totient is φ = 81303510.

The previous prime is 81303493. The next prime is 81303517. The reversal of 81303511 is 11530318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81303511 - 2⁵ = 81303479 is a prime.

It is a super-2 number, since 2×81303511² = 13220521801854242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81303517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40651755 + 40651756.

It is an arithmetic number, because the mean of its divisors is an integer number (40651756).

Almost surely, 2^81303511 is an apocalyptic number.

81303511 is a deficient number, since it is larger than the sum of its proper divisors (1).

81303511 is an equidigital number, since it uses as much as digits as its factorization.

81303511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 81303511 is about 9016.8459563198. The cubic root of 81303511 is about 433.2146155390.

Adding to 81303511 its reverse (11530318), we get a palindrome (92833829).

The spelling of 81303511 in words is "eighty-one million, three hundred three thousand, five hundred eleven".