87811421 has 2 divisors, whose sum is σ = 87811422. Its totient is φ = 87811420.

The previous prime is 87811417. The next prime is 87811429. The reversal of 87811421 is 12411878.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81631225 + 6180196 = 9035^2 + 2486^2 .

It is a cyclic number.

It is not a de Polignac number, because 87811421 - 2² = 87811417 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87811429) 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 as a sum of consecutive naturals, namely, 43905710 + 43905711.

It is an arithmetic number, because the mean of its divisors is an integer number (43905711).

Almost surely, 2^87811421 is an apocalyptic number.

It is an amenable number.

87811421 is a deficient number, since it is larger than the sum of its proper divisors (1).

87811421 is an equidigital number, since it uses as much as digits as its factorization.

87811421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3584, while the sum is 32.

The square root of 87811421 is about 9370.7748345588. The cubic root of 87811421 is about 444.4780666902.

The spelling of 87811421 in words is "eighty-seven million, eight hundred eleven thousand, four hundred twenty-one".