87856621 has 2 divisors, whose sum is σ = 87856622. Its totient is φ = 87856620.

The previous prime is 87856597. The next prime is 87856649. The reversal of 87856621 is 12665878.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46717225 + 41139396 = 6835^2 + 6414^2 .

It is a cyclic number.

It is not a de Polignac number, because 87856621 - 2¹¹ = 87854573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87856661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43928310 + 43928311.

It is an arithmetic number, because the mean of its divisors is an integer number (43928311).

Almost surely, 2^87856621 is an apocalyptic number.

It is an amenable number.

87856621 is a deficient number, since it is larger than the sum of its proper divisors (1).

87856621 is an equidigital number, since it uses as much as digits as its factorization.

87856621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 43.

The square root of 87856621 is about 9373.1862778886. The cubic root of 87856621 is about 444.5543170696.

The spelling of 87856621 in words is "eighty-seven million, eight hundred fifty-six thousand, six hundred twenty-one".