400445320 has 32 divisors (see below), whose sum is σ = 982912320. Its totient is φ = 145616320.

The previous prime is 400445317. The next prime is 400445329. The reversal of 400445320 is 23544004.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 400445291 and 400445300.

It is not an unprimeable number, because it can be changed into a prime (400445329) 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 7 ways as a sum of consecutive naturals, for example, 454612 + ... + 455491.

It is an arithmetic number, because the mean of its divisors is an integer number (30716010).

Almost surely, 2^400445320 is an apocalyptic number.

400445320 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400445320 is an abundant number, since it is smaller than the sum of its proper divisors (582467000).

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

400445320 is a wasteful number, since it uses less digits than its factorization.

400445320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910125 (or 910121 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 22.

The square root of 400445320 is about 20011.1299031314. The cubic root of 400445320 is about 737.0796271392.

Adding to 400445320 its reverse (23544004), we get a palindrome (423989324).

It can be divided in two parts, 400445 and 320, that multiplied together give a square (128142400 = 11320²).

The spelling of 400445320 in words is "four hundred million, four hundred forty-five thousand, three hundred twenty".