398821877 has 4 divisors (see below), whose sum is σ = 398956236. Its totient is φ = 398687520.

The previous prime is 398821859. The next prime is 398821957. The reversal of 398821877 is 778128893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 778128893 = 23 ⋅33831691.

It can be written as a sum of positive squares in 2 ways, for example, as 150160516 + 248661361 = 12254^2 + 15769^2 .

It is a cyclic number.

It is not a de Polignac number, because 398821877 - 2¹⁶ = 398756341 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 (398821807) 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, 62624 + ... + 68697.

It is an arithmetic number, because the mean of its divisors is an integer number (99739059).

Almost surely, 2^398821877 is an apocalyptic number.

It is an amenable number.

398821877 is a deficient number, since it is larger than the sum of its proper divisors (134359).

398821877 is a wasteful number, since it uses less digits than its factorization.

398821877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134358.

The product of its digits is 1354752, while the sum is 53.

The square root of 398821877 is about 19970.5252059128. The cubic root of 398821877 is about 736.0822146708.

The spelling of 398821877 in words is "three hundred ninety-eight million, eight hundred twenty-one thousand, eight hundred seventy-seven".