398645820 has 96 divisors (see below), whose sum is σ = 1243146240. Its totient is φ = 106056000.

The previous prime is 398645791. The next prime is 398645827. The reversal of 398645820 is 28546893.

398645820 is a `hidden beast` number, since 3 + 9 + 8 + 64 + 582 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398645827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 405049 + ... + 406031.

It is an arithmetic number, because the mean of its divisors is an integer number (12949440).

Almost surely, 2^398645820 is an apocalyptic number.

398645820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398645820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (621573120).

398645820 is an abundant number, since it is smaller than the sum of its proper divisors (844500420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

398645820 is a wasteful number, since it uses less digits than its factorization.

398645820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1752 (or 1744 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 398645820 is about 19966.1167982159. The cubic root of 398645820 is about 735.9738860260.

The spelling of 398645820 in words is "three hundred ninety-eight million, six hundred forty-five thousand, eight hundred twenty".