87630921 has 12 divisors (see below), whose sum is σ = 144660672. Its totient is φ = 50074776.

The previous prime is 87630859. The next prime is 87630929. The reversal of 87630921 is 12903678.

It is not a de Polignac number, because 87630921 - 2¹⁵ = 87598153 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (87630929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 695421 + ... + 695546.

It is an arithmetic number, because the mean of its divisors is an integer number (12055056).

Almost surely, 2^87630921 is an apocalyptic number.

It is an amenable number.

87630921 is a deficient number, since it is larger than the sum of its proper divisors (57029751).

87630921 is a wasteful number, since it uses less digits than its factorization.

87630921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1390980 (or 1390977 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 87630921 is about 9361.1388730218. The cubic root of 87630921 is about 444.1733101113.

The spelling of 87630921 in words is "eighty-seven million, six hundred thirty thousand, nine hundred twenty-one".