400543645 has 4 divisors (see below), whose sum is σ = 480652380. Its totient is φ = 320434912.

The previous prime is 400543639. The next prime is 400543669. The reversal of 400543645 is 546345004.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 312971481 + 87572164 = 17691^2 + 9358^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400543645 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40054360 + ... + 40054369.

It is an arithmetic number, because the mean of its divisors is an integer number (120163095).

Almost surely, 2^400543645 is an apocalyptic number.

It is an amenable number.

400543645 is a deficient number, since it is larger than the sum of its proper divisors (80108735).

400543645 is an equidigital number, since it uses as much as digits as its factorization.

400543645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80108734.

The product of its (nonzero) digits is 28800, while the sum is 31.

The square root of 400543645 is about 20013.5865101685. The cubic root of 400543645 is about 737.1399495019.

Adding to 400543645 its reverse (546345004), we get a palindrome (946888649).

The spelling of 400543645 in words is "four hundred million, five hundred forty-three thousand, six hundred forty-five".