401023644 has 72 divisors (see below), whose sum is σ = 1098654480. Its totient is φ = 113508864.

The previous prime is 401023639. The next prime is 401023661. The reversal of 401023644 is 446320104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60964 + ... + 67220.

It is an arithmetic number, because the mean of its divisors is an integer number (15259090).

Almost surely, 2^401023644 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 401023644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (549327240).

401023644 is an abundant number, since it is smaller than the sum of its proper divisors (697630836).

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

401023644 is a wasteful number, since it uses less digits than its factorization.

401023644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6387 (or 6378 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 401023644 is about 20025.5747483062. The cubic root of 401023644 is about 737.4342871260.

Adding to 401023644 its reverse (446320104), we get a palindrome (847343748).

The spelling of 401023644 in words is "four hundred one million, twenty-three thousand, six hundred forty-four".