87811573 has 2 divisors, whose sum is σ = 87811574. Its totient is φ = 87811572.

The previous prime is 87811567. The next prime is 87811601. The reversal of 87811573 is 37511878.

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., 81848209 + 5963364 = 9047^2 + 2442^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87811573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87811973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43905786 + 43905787.

It is an arithmetic number, because the mean of its divisors is an integer number (43905787).

Almost surely, 2^87811573 is an apocalyptic number.

It is an amenable number.

87811573 is a deficient number, since it is larger than the sum of its proper divisors (1).

87811573 is an equidigital number, since it uses as much as digits as its factorization.

87811573 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47040, while the sum is 40.

The square root of 87811573 is about 9370.7829448771. The cubic root of 87811573 is about 444.4783231513.

The spelling of 87811573 in words is "eighty-seven million, eight hundred eleven thousand, five hundred seventy-three".