698638821 has 4 divisors (see below), whose sum is σ = 931518432. Its totient is φ = 465759212.

The previous prime is 698638819. The next prime is 698638859. The reversal of 698638821 is 128836896.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 698638821 - 2¹ = 698638819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (698638861) 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, 116439801 + ... + 116439806.

It is an arithmetic number, because the mean of its divisors is an integer number (232879608).

Almost surely, 2^698638821 is an apocalyptic number.

It is an amenable number.

698638821 is a deficient number, since it is larger than the sum of its proper divisors (232879611).

698638821 is a wasteful number, since it uses less digits than its factorization.

698638821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232879610.

The product of its digits is 995328, while the sum is 51.

The square root of 698638821 is about 26431.7767280219. The cubic root of 698638821 is about 887.3281062583.

The spelling of 698638821 in words is "six hundred ninety-eight million, six hundred thirty-eight thousand, eight hundred twenty-one".