398884781 has 12 divisors (see below), whose sum is σ = 419629440. Its totient is φ = 378662280.

The previous prime is 398884769. The next prime is 398884789. The reversal of 398884781 is 187488893.

It is not a de Polignac number, because 398884781 - 2¹⁴ = 398868397 is a prime.

It is a super-2 number, since 2×398884781² = 318218137026835922, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (3096576) is a multiple of the sum of its prime factors (1024).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398884789) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 853910 + ... + 854376.

It is an arithmetic number, because the mean of its divisors is an integer number (34969120).

Almost surely, 2^398884781 is an apocalyptic number.

398884781 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

398884781 is a deficient number, since it is larger than the sum of its proper divisors (20744659).

398884781 is an frugal number, since it uses more digits than its factorization.

398884781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1024 (or 557 counting only the distinct ones).

The product of its digits is 3096576, while the sum is 56.

The square root of 398884781 is about 19972.1000648405. The cubic root of 398884781 is about 736.1209120478.

The spelling of 398884781 in words is "three hundred ninety-eight million, eight hundred eighty-four thousand, seven hundred eighty-one".