87719897 has 2 divisors, whose sum is σ = 87719898. Its totient is φ = 87719896.

The previous prime is 87719893. The next prime is 87719899. The reversal of 87719897 is 79891778.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65545216 + 22174681 = 8096^2 + 4709^2 .

It is a cyclic number.

It is not a de Polignac number, because 87719897 - 2² = 87719893 is a prime.

Together with 87719899, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87719893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43859948 + 43859949.

It is an arithmetic number, because the mean of its divisors is an integer number (43859949).

Almost surely, 2^87719897 is an apocalyptic number.

It is an amenable number.

87719897 is a deficient number, since it is larger than the sum of its proper divisors (1).

87719897 is an equidigital number, since it uses as much as digits as its factorization.

87719897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 56.

The square root of 87719897 is about 9365.8900804996. The cubic root of 87719897 is about 444.3235896235.

The spelling of 87719897 in words is "eighty-seven million, seven hundred nineteen thousand, eight hundred ninety-seven".