87840661 has 2 divisors, whose sum is σ = 87840662. Its totient is φ = 87840660.

The previous prime is 87840659. The next prime is 87840673. The reversal of 87840661 is 16604878.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87778161 + 62500 = 9369^2 + 250^2 .

It is a cyclic number.

It is not a de Polignac number, because 87840661 - 2¹ = 87840659 is a prime.

It is a super-3 number, since 3×87840661³ (a number of 25 digits) contains 333 as substring.

Together with 87840659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87840631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43920330 + 43920331.

It is an arithmetic number, because the mean of its divisors is an integer number (43920331).

Almost surely, 2^87840661 is an apocalyptic number.

It is an amenable number.

87840661 is a deficient number, since it is larger than the sum of its proper divisors (1).

87840661 is an equidigital number, since it uses as much as digits as its factorization.

87840661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 87840661 is about 9372.3348745123. The cubic root of 87840661 is about 444.5273962506.

The spelling of 87840661 in words is "eighty-seven million, eight hundred forty thousand, six hundred sixty-one".