87721843 has 16 divisors (see below), whose sum is σ = 97850880. Its totient is φ = 77968800.

The previous prime is 87721811. The next prime is 87721877. The reversal of 87721843 is 34812778.

It is a cyclic number.

It is not a de Polignac number, because 87721843 - 2⁵ = 87721811 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 87721796 and 87721805.

It is not an unprimeable number, because it can be changed into a prime (87721243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 160096 + ... + 160642.

It is an arithmetic number, because the mean of its divisors is an integer number (6115680).

Almost surely, 2^87721843 is an apocalyptic number.

87721843 is a deficient number, since it is larger than the sum of its proper divisors (10129037).

87721843 is a wasteful number, since it uses less digits than its factorization.

87721843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 858.

The product of its digits is 75264, while the sum is 40.

The square root of 87721843 is about 9365.9939675402. The cubic root of 87721843 is about 444.3268752609.

The spelling of 87721843 in words is "eighty-seven million, seven hundred twenty-one thousand, eight hundred forty-three".