87921871 has 2 divisors, whose sum is σ = 87921872. Its totient is φ = 87921870.

The previous prime is 87921853. The next prime is 87921901. The reversal of 87921871 is 17812978.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87921871 - 2⁵ = 87921839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87921811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43960935 + 43960936.

It is an arithmetic number, because the mean of its divisors is an integer number (43960936).

Almost surely, 2^87921871 is an apocalyptic number.

87921871 is a deficient number, since it is larger than the sum of its proper divisors (1).

87921871 is an equidigital number, since it uses as much as digits as its factorization.

87921871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 43.

The square root of 87921871 is about 9376.6663052494. Note that the first 3 decimals coincide. The cubic root of 87921871 is about 444.6643447895.

The spelling of 87921871 in words is "eighty-seven million, nine hundred twenty-one thousand, eight hundred seventy-one".