401642220 has 144 divisors (see below), whose sum is σ = 1328382720. Its totient is φ = 90389376.

The previous prime is 401642209. The next prime is 401642233. The reversal of 401642220 is 22246104.

It is a super-2 number, since 2×401642220² = 322632945773056800, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 195961 + ... + 197999.

It is an arithmetic number, because the mean of its divisors is an integer number (9224880).

Almost surely, 2^401642220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 401642220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (664191360).

401642220 is an abundant number, since it is smaller than the sum of its proper divisors (926740500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

401642220 is a wasteful number, since it uses less digits than its factorization.

401642220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132 (or 2123 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 401642220 is about 20041.0134474283. The cubic root of 401642220 is about 737.8132546494.

Adding to 401642220 its reverse (22246104), we get a palindrome (423888324).

The spelling of 401642220 in words is "four hundred one million, six hundred forty-two thousand, two hundred twenty".