87241621 has 2 divisors, whose sum is σ = 87241622. Its totient is φ = 87241620.

The previous prime is 87241619. The next prime is 87241669. The reversal of 87241621 is 12614278.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87048900 + 192721 = 9330^2 + 439^2 .

It is a cyclic number.

It is not a de Polignac number, because 87241621 - 2¹ = 87241619 is a prime.

It is a super-2 number, since 2×87241621² = 15222200869415282, which contains 22 as substring.

Together with 87241619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87241681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43620810 + 43620811.

It is an arithmetic number, because the mean of its divisors is an integer number (43620811).

Almost surely, 2^87241621 is an apocalyptic number.

It is an amenable number.

87241621 is a deficient number, since it is larger than the sum of its proper divisors (1).

87241621 is an equidigital number, since it uses as much as digits as its factorization.

87241621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 31.

The square root of 87241621 is about 9340.3223177790. The cubic root of 87241621 is about 443.5145876649.

Adding to 87241621 its reverse (12614278), we get a palindrome (99855899).

The spelling of 87241621 in words is "eighty-seven million, two hundred forty-one thousand, six hundred twenty-one".