87145909 has 2 divisors, whose sum is σ = 87145910. Its totient is φ = 87145908.

The previous prime is 87145901. The next prime is 87145963. The reversal of 87145909 is 90954178.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84180625 + 2965284 = 9175^2 + 1722^2 .

It is a cyclic number.

It is not a de Polignac number, because 87145909 - 2³ = 87145901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87145901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43572954 + 43572955.

It is an arithmetic number, because the mean of its divisors is an integer number (43572955).

Almost surely, 2^87145909 is an apocalyptic number.

It is an amenable number.

87145909 is a deficient number, since it is larger than the sum of its proper divisors (1).

87145909 is an equidigital number, since it uses as much as digits as its factorization.

87145909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 87145909 is about 9335.1973198214. The cubic root of 87145909 is about 443.3523363567.

The spelling of 87145909 in words is "eighty-seven million, one hundred forty-five thousand, nine hundred nine".