400002500 has 30 divisors (see below), whose sum is σ = 874730934. Its totient is φ = 160000000.

The previous prime is 400002461. The next prime is 400002509. The reversal of 400002500 is 5200004.

400002500 = T₈₉ + T₉₀ + ... + T₁₃₃₈.

It can be written as a sum of positive squares in 5 ways, for example, as 31899904 + 368102596 = 5648^2 + 19186^2 .

It is a sliding number, since 400002500 = 2500 + 400000000 and 1/2500 + 1/400000000 = 0.000400002500.

It is not an unprimeable number, because it can be changed into a prime (400002509) 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 9 ways as a sum of consecutive naturals, for example, 77501 + ... + 82500.

Almost surely, 2^400002500 is an apocalyptic number.

It is an amenable number.

400002500 is an abundant number, since it is smaller than the sum of its proper divisors (474728434).

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

400002500 is a wasteful number, since it uses less digits than its factorization.

400002500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160025 (or 160008 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 11.

The square root of 400002500 is about 20000.0624999023. The cubic root of 400002500 is about 736.8078347380.

Adding to 400002500 its reverse (5200004), we get a palindrome (405202504).

It can be divided in two parts, 40000 and 2500, that multiplied together give a 8-th power (100000000 = 10⁸).

The spelling of 400002500 in words is "four hundred million, two thousand, five hundred".