400021210 has 64 divisors (see below), whose sum is σ = 768144384. Its totient is φ = 149760000.

The previous prime is 400021201. The next prime is 400021213. The reversal of 400021210 is 12120004.

400021210 = T₈₄ + T₈₅ + ... + T₁₃₃₈.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (400021213) 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, 1593585 + ... + 1593835.

It is an arithmetic number, because the mean of its divisors is an integer number (12002256).

Almost surely, 2^400021210 is an apocalyptic number.

400021210 is a deficient number, since it is larger than the sum of its proper divisors (368123174).

400021210 is a wasteful number, since it uses less digits than its factorization.

400021210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 400021210 is about 20000.5302429711. The cubic root of 400021210 is about 736.8193225492.

Adding to 400021210 its reverse (12120004), we get a palindrome (412141214).

The spelling of 400021210 in words is "four hundred million, twenty-one thousand, two hundred ten".