87192989 has 4 divisors (see below), whose sum is σ = 93900156. Its totient is φ = 80485824.

The previous prime is 87192971. The next prime is 87193061. The reversal of 87192989 is 98929178.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98929178 = 2 ⋅49464589.

It can be written as a sum of positive squares in 2 ways, for example, as 57304900 + 29888089 = 7570^2 + 5467^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87192989 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 87192989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87192689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3353564 + ... + 3353589.

It is an arithmetic number, because the mean of its divisors is an integer number (23475039).

Almost surely, 2^87192989 is an apocalyptic number.

It is an amenable number.

87192989 is a deficient number, since it is larger than the sum of its proper divisors (6707167).

87192989 is a wasteful number, since it uses less digits than its factorization.

87192989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6707166.

The product of its digits is 653184, while the sum is 53.

The square root of 87192989 is about 9337.7186185920. The cubic root of 87192989 is about 443.4321613709.

The spelling of 87192989 in words is "eighty-seven million, one hundred ninety-two thousand, nine hundred eighty-nine".