87640723 has 2 divisors, whose sum is σ = 87640724. Its totient is φ = 87640722.

The previous prime is 87640717. The next prime is 87640793. The reversal of 87640723 is 32704678.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87640723 - 2⁵ = 87640691 is a prime.

It is not a weakly prime, because it can be changed into another prime (87640793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43820361 + 43820362.

It is an arithmetic number, because the mean of its divisors is an integer number (43820362).

Almost surely, 2^87640723 is an apocalyptic number.

87640723 is a deficient number, since it is larger than the sum of its proper divisors (1).

87640723 is an equidigital number, since it uses as much as digits as its factorization.

87640723 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 37.

The square root of 87640723 is about 9361.6624057910. The cubic root of 87640723 is about 444.1898705690.

The spelling of 87640723 in words is "eighty-seven million, six hundred forty thousand, seven hundred twenty-three".