87995021 has 4 divisors (see below), whose sum is σ = 88773852. Its totient is φ = 87216192.

The previous prime is 87994993. The next prime is 87995041. The reversal of 87995021 is 12059978.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25110121 + 62884900 = 5011^2 + 7930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87995021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87995021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87995041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 389246 + ... + 389471.

It is an arithmetic number, because the mean of its divisors is an integer number (22193463).

Almost surely, 2^87995021 is an apocalyptic number.

It is an amenable number.

87995021 is a deficient number, since it is larger than the sum of its proper divisors (778831).

87995021 is a wasteful number, since it uses less digits than its factorization.

87995021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778830.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 87995021 is about 9380.5661343013. The cubic root of 87995021 is about 444.7876291701.

The spelling of 87995021 in words is "eighty-seven million, nine hundred ninety-five thousand, twenty-one".