898071821 has 4 divisors (see below), whose sum is σ = 898230012. Its totient is φ = 897913632.

The previous prime is 898071787. The next prime is 898071827. The reversal of 898071821 is 128170898.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 765130921 + 132940900 = 27661^2 + 11530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-898071821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (898071827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70250 + ... + 82043.

It is an arithmetic number, because the mean of its divisors is an integer number (224557503).

Almost surely, 2^898071821 is an apocalyptic number.

It is an amenable number.

898071821 is a deficient number, since it is larger than the sum of its proper divisors (158191).

898071821 is a wasteful number, since it uses less digits than its factorization.

898071821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158190.

The product of its (nonzero) digits is 64512, while the sum is 44.

The square root of 898071821 is about 29967.8464524897. The cubic root of 898071821 is about 964.7993966758.

The spelling of 898071821 in words is "eight hundred ninety-eight million, seventy-one thousand, eight hundred twenty-one".