400236221 has 32 divisors (see below), whose sum is σ = 520058880. Its totient is φ = 298872000.

The previous prime is 400236211. The next prime is 400236227. The reversal of 400236221 is 122632004.

It is not a de Polignac number, because 400236221 - 2⁶ = 400236157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400236193 and 400236202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400236227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 336590 + ... + 337776.

It is an arithmetic number, because the mean of its divisors is an integer number (16251840).

Almost surely, 2^400236221 is an apocalyptic number.

It is an amenable number.

400236221 is a deficient number, since it is larger than the sum of its proper divisors (119822659).

400236221 is a wasteful number, since it uses less digits than its factorization.

400236221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1385.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 400236221 is about 20005.9046533767. The cubic root of 400236221 is about 736.9513121201.

Adding to 400236221 its reverse (122632004), we get a palindrome (522868225).

The spelling of 400236221 in words is "four hundred million, two hundred thirty-six thousand, two hundred twenty-one".