400516221 has 16 divisors (see below), whose sum is σ = 616239104. Its totient is φ = 226643184.

The previous prime is 400516211. The next prime is 400516223. The reversal of 400516221 is 122615004.

It is not a de Polignac number, because 400516221 - 2⁵ = 400516189 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400516223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90421 + ... + 94746.

It is an arithmetic number, because the mean of its divisors is an integer number (38514944).

Almost surely, 2^400516221 is an apocalyptic number.

It is an amenable number.

400516221 is a deficient number, since it is larger than the sum of its proper divisors (215722883).

400516221 is a wasteful number, since it uses less digits than its factorization.

400516221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185280.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 400516221 is about 20012.9013638703. The cubic root of 400516221 is about 737.1231258776.

The spelling of 400516221 in words is "four hundred million, five hundred sixteen thousand, two hundred twenty-one".