81307801 has 2 divisors, whose sum is σ = 81307802. Its totient is φ = 81307800.

The previous prime is 81307789. The next prime is 81307847. The reversal of 81307801 is 10870318.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65626201 + 15681600 = 8101^2 + 3960^2 .

It is a cyclic number.

It is not a de Polignac number, because 81307801 - 2⁵ = 81307769 is a prime.

It is a super-2 number, since 2×81307801² = 13221917006911202, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81307801.

It is not a weakly prime, because it can be changed into another prime (81307871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40653900 + 40653901.

It is an arithmetic number, because the mean of its divisors is an integer number (40653901).

Almost surely, 2^81307801 is an apocalyptic number.

It is an amenable number.

81307801 is a deficient number, since it is larger than the sum of its proper divisors (1).

81307801 is an equidigital number, since it uses as much as digits as its factorization.

81307801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 81307801 is about 9017.0838412427. The cubic root of 81307801 is about 433.2222349640. Note that the first 4 decimals are identical.

It can be divided in two parts, 8130 and 7801, that added together give a triangular number (15931 = T₁₇₈).

The spelling of 81307801 in words is "eighty-one million, three hundred seven thousand, eight hundred one".