400615645 has 4 divisors (see below), whose sum is σ = 480738780. Its totient is φ = 320492512.

The previous prime is 400615643. The next prime is 400615667. The reversal of 400615645 is 546516004.

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 267028281 + 133587364 = 16341^2 + 11558^2 .

It is a cyclic number.

It is not a de Polignac number, because 400615645 - 2¹ = 400615643 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400615643) 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 3 ways as a sum of consecutive naturals, for example, 40061560 + ... + 40061569.

It is an arithmetic number, because the mean of its divisors is an integer number (120184695).

Almost surely, 2^400615645 is an apocalyptic number.

It is an amenable number.

400615645 is a deficient number, since it is larger than the sum of its proper divisors (80123135).

400615645 is an equidigital number, since it uses as much as digits as its factorization.

400615645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80123134.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 400615645 is about 20015.3852073848. The cubic root of 400615645 is about 737.1841152228.

The spelling of 400615645 in words is "four hundred million, six hundred fifteen thousand, six hundred forty-five".