87819661 has 2 divisors, whose sum is σ = 87819662. Its totient is φ = 87819660.

The previous prime is 87819643. The next prime is 87819679. The reversal of 87819661 is 16691878.

It is a balanced prime because it is at equal distance from previous prime (87819643) and next prime (87819679).

It can be written as a sum of positive squares in only one way, i.e., 64722025 + 23097636 = 8045^2 + 4806^2 .

It is a cyclic number.

It is not a de Polignac number, because 87819661 - 2¹³ = 87811469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87816661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43909830 + 43909831.

It is an arithmetic number, because the mean of its divisors is an integer number (43909831).

Almost surely, 2^87819661 is an apocalyptic number.

It is an amenable number.

87819661 is a deficient number, since it is larger than the sum of its proper divisors (1).

87819661 is an equidigital number, since it uses as much as digits as its factorization.

87819661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 46.

The square root of 87819661 is about 9371.2144890617. The cubic root of 87819661 is about 444.4919691518.

The spelling of 87819661 in words is "eighty-seven million, eight hundred nineteen thousand, six hundred sixty-one".