81140747 has 2 divisors, whose sum is σ = 81140748. Its totient is φ = 81140746.

The previous prime is 81140743. The next prime is 81140767. The reversal of 81140747 is 74704118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81140747 - 2² = 81140743 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81140743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40570373 + 40570374.

It is an arithmetic number, because the mean of its divisors is an integer number (40570374).

Almost surely, 2^81140747 is an apocalyptic number.

81140747 is a deficient number, since it is larger than the sum of its proper divisors (1).

81140747 is an equidigital number, since it uses as much as digits as its factorization.

81140747 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6272, while the sum is 32.

The square root of 81140747 is about 9007.8158839976. The cubic root of 81140747 is about 432.9253338568.

The spelling of 81140747 in words is "eighty-one million, one hundred forty thousand, seven hundred forty-seven".