400531551 has 32 divisors (see below), whose sum is σ = 626055168. Its totient is φ = 223050240.

The previous prime is 400531531. The next prime is 400531567. The reversal of 400531551 is 155135004.

It is not a de Polignac number, because 400531551 - 2⁶ = 400531487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400531511) 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 31 ways as a sum of consecutive naturals, for example, 143370 + ... + 146136.

It is an arithmetic number, because the mean of its divisors is an integer number (19564224).

Almost surely, 2^400531551 is an apocalyptic number.

400531551 is a deficient number, since it is larger than the sum of its proper divisors (225523617).

400531551 is a wasteful number, since it uses less digits than its factorization.

400531551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2951.

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 400531551 is about 20013.2843631424. The cubic root of 400531551 is about 737.1325303684.

Adding to 400531551 its reverse (155135004), we get a palindrome (555666555).

The spelling of 400531551 in words is "four hundred million, five hundred thirty-one thousand, five hundred fifty-one".