400402251 has 32 divisors (see below), whose sum is σ = 605472000. Its totient is φ = 261455040.

The previous prime is 400402213. The next prime is 400402273. The reversal of 400402251 is 152204004.

400402251 is a `hidden beast` number, since 400 + 40 + 225 + 1 = 666.

It is not a de Polignac number, because 400402251 - 2⁹ = 400401739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (400402201) 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, 381175 + ... + 382223.

It is an arithmetic number, because the mean of its divisors is an integer number (18921000).

Almost surely, 2^400402251 is an apocalyptic number.

400402251 is a deficient number, since it is larger than the sum of its proper divisors (205069749).

400402251 is a wasteful number, since it uses less digits than its factorization.

400402251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336 (or 1330 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 400402251 is about 20010.0537480538. The cubic root of 400402251 is about 737.0532012087.

Adding to 400402251 its reverse (152204004), we get a palindrome (552606255).

The spelling of 400402251 in words is "four hundred million, four hundred two thousand, two hundred fifty-one".