87819839 has 2 divisors, whose sum is σ = 87819840. Its totient is φ = 87819838.

The previous prime is 87819821. The next prime is 87819899. The reversal of 87819839 is 93891878.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87819839 - 2⁸ = 87819583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87819899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43909919 + 43909920.

It is an arithmetic number, because the mean of its divisors is an integer number (43909920).

Almost surely, 2^87819839 is an apocalyptic number.

87819839 is a deficient number, since it is larger than the sum of its proper divisors (1).

87819839 is an equidigital number, since it uses as much as digits as its factorization.

87819839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 53.

The square root of 87819839 is about 9371.2239862251. The cubic root of 87819839 is about 444.4922694623.

The spelling of 87819839 in words is "eighty-seven million, eight hundred nineteen thousand, eight hundred thirty-nine".