401640 has 32 divisors (see below), whose sum is σ = 1205280. Its totient is φ = 107072.

The previous prime is 401629. The next prime is 401651. The reversal of 401640 is 46104.

It is an interprime number because it is at equal distance from previous prime (401629) and next prime (401651).

It is a super-2 number, since 2×401640² = 322629379200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1554 + ... + 1793.

It is an arithmetic number, because the mean of its divisors is an integer number (37665).

2⁴⁰¹⁶⁴⁰ is an apocalyptic number.

401640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

401640 is an abundant number, since it is smaller than the sum of its proper divisors (803640).

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

401640 is a wasteful number, since it uses less digits than its factorization.

401640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3361 (or 3357 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 401640 is about 633.7507396445. The cubic root of 401640 is about 73.7811895273.

Adding to 401640 its reverse (46104), we get a palindrome (447744).

The spelling of 401640 in words is "four hundred one thousand, six hundred forty".