87919661 has 2 divisors, whose sum is σ = 87919662. Its totient is φ = 87919660.

The previous prime is 87919603. The next prime is 87919673. The reversal of 87919661 is 16691978.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74822500 + 13097161 = 8650^2 + 3619^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87919661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87919261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43959830 + 43959831.

It is an arithmetic number, because the mean of its divisors is an integer number (43959831).

Almost surely, 2^87919661 is an apocalyptic number.

It is an amenable number.

87919661 is a deficient number, since it is larger than the sum of its proper divisors (1).

87919661 is an equidigital number, since it uses as much as digits as its factorization.

87919661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 47.

The square root of 87919661 is about 9376.5484587880. The cubic root of 87919661 is about 444.6606190709.

The spelling of 87919661 in words is "eighty-seven million, nine hundred nineteen thousand, six hundred sixty-one".