87021939 has 8 divisors (see below), whose sum is σ = 116346880. Its totient is φ = 57855816.

The previous prime is 87021911. The next prime is 87021943. The reversal of 87021939 is 93912078.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 87021939 - 2⁹ = 87021427 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 87021897 and 87021906.

It is not an unprimeable number, because it can be changed into a prime (87021839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38419 + ... + 40620.

It is an arithmetic number, because the mean of its divisors is an integer number (14543360).

Almost surely, 2^87021939 is an apocalyptic number.

87021939 is a deficient number, since it is larger than the sum of its proper divisors (29324941).

87021939 is a wasteful number, since it uses less digits than its factorization.

87021939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79409.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 87021939 is about 9328.5550328012. Note that the first 3 decimals coincide. The cubic root of 87021939 is about 443.1420053048.

The spelling of 87021939 in words is "eighty-seven million, twenty-one thousand, nine hundred thirty-nine".