87407821 has 2 divisors, whose sum is σ = 87407822. Its totient is φ = 87407820.

The previous prime is 87407807. The next prime is 87407833. The reversal of 87407821 is 12870478.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75255625 + 12152196 = 8675^2 + 3486^2 .

It is a cyclic number.

It is not a de Polignac number, because 87407821 - 2²¹ = 85310669 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87407861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43703910 + 43703911.

It is an arithmetic number, because the mean of its divisors is an integer number (43703911).

Almost surely, 2^87407821 is an apocalyptic number.

It is an amenable number.

87407821 is a deficient number, since it is larger than the sum of its proper divisors (1).

87407821 is an equidigital number, since it uses as much as digits as its factorization.

87407821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25088, while the sum is 37.

The square root of 87407821 is about 9349.2149937842. The cubic root of 87407821 is about 443.7960487556.

It can be divided in two parts, 8740 and 7821, that added together give a palindrome (16561).

The spelling of 87407821 in words is "eighty-seven million, four hundred seven thousand, eight hundred twenty-one".