8400400 has 30 divisors (see below), whose sum is σ = 20182922. Its totient is φ = 3360000.

The previous prime is 8400377. The next prime is 8400409. The reversal of 8400400 is 40048.

It can be written as a sum of positive squares in 3 ways, for example, as 82944 + 8317456 = 288^2 + 2884^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (8400409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10101 + ... + 10900.

Almost surely, 2^8400400 is an apocalyptic number.

8400400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8400400 is an abundant number, since it is smaller than the sum of its proper divisors (11782522).

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

8400400 is a wasteful number, since it uses less digits than its factorization.

8400400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21019 (or 21008 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 8400400 is about 2898.3443549723. The cubic root of 8400400 is about 203.2824979669.

Adding to 8400400 its reverse (40048), we get a palindrome (8440448).

The spelling of 8400400 in words is "eight million, four hundred thousand, four hundred".