87991620 has 48 divisors (see below), whose sum is σ = 249359040. Its totient is φ = 23180416.

The previous prime is 87991613. The next prime is 87991621. The reversal of 87991620 is 2619978.

It is not an unprimeable number, because it can be changed into a prime (87991621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3855 + ... + 13814.

It is an arithmetic number, because the mean of its divisors is an integer number (5194980).

Almost surely, 2^87991620 is an apocalyptic number.

It is an amenable number.

87991620 is an abundant number, since it is smaller than the sum of its proper divisors (161367420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

87991620 is a wasteful number, since it uses less digits than its factorization.

87991620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17764 (or 17762 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 87991620 is about 9380.3848535121. The cubic root of 87991620 is about 444.7818987618.

The spelling of 87991620 in words is "eighty-seven million, nine hundred ninety-one thousand, six hundred twenty".