1000400000 has 192 divisors, whose sum is σ = 2593662120. Its totient is φ = 384000000.

The previous prime is 1000399997. The next prime is 1000400017. The reversal of 1000400000 is 40001.

It can be written as a sum of positive squares in 12 ways, for example, as 944209984 + 56190016 = 30728^2 + 7496^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16399970 + ... + 16400030.

Almost surely, 2^1000400000 is an apocalyptic number.

1000400000 is a gapful number since it is divisible by the number (10) 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 1000400000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1296831060).

1000400000 is an abundant number, since it is smaller than the sum of its proper divisors (1593262120).

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

1000400000 is an frugal number, since it uses more digits than its factorization.

1000400000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 1000400000 is about 31629.1005246751. The cubic root of 1000400000 is about 1000.1333155595.

Adding to 1000400000 its reverse (40001), we get a palindrome (1000440001).

It can be divided in two parts, 1000 and 400000, that multiplied together give a square (400000000 = 20000²).

The spelling of 1000400000 in words is "one billion, four hundred thousand".