400455521 has 4 divisors (see below), whose sum is σ = 403378692. Its totient is φ = 397532352.

The previous prime is 400455499. The next prime is 400455593. The reversal of 400455521 is 125554004.

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 287777296 + 112678225 = 16964^2 + 10615^2 .

It is not a de Polignac number, because 400455521 - 2¹⁸ = 400193377 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (400455221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1461380 + ... + 1461653.

It is an arithmetic number, because the mean of its divisors is an integer number (100844673).

Almost surely, 2^400455521 is an apocalyptic number.

It is an amenable number.

400455521 is a deficient number, since it is larger than the sum of its proper divisors (2923171).

400455521 is a wasteful number, since it uses less digits than its factorization.

400455521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2923170.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 400455521 is about 20011.3847846670. The cubic root of 400455521 is about 737.0858859092.

The spelling of 400455521 in words is "four hundred million, four hundred fifty-five thousand, five hundred twenty-one".