401317821 has 40 divisors (see below), whose sum is σ = 611582400. Its totient is φ = 262215360.

The previous prime is 401317817. The next prime is 401317837. The reversal of 401317821 is 128713104.

It is not a de Polignac number, because 401317821 - 2² = 401317817 is a prime.

It is a super-5 number, since 5×401317821⁵ (a number of 44 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401317801) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1290256 + ... + 1290566.

It is an arithmetic number, because the mean of its divisors is an integer number (15289560).

Almost surely, 2^401317821 is an apocalyptic number.

It is an amenable number.

401317821 is a deficient number, since it is larger than the sum of its proper divisors (210264579).

401317821 is a wasteful number, since it uses less digits than its factorization.

401317821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591 (or 582 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 401317821 is about 20032.9184344169. The cubic root of 401317821 is about 737.6145617685.

The spelling of 401317821 in words is "four hundred one million, three hundred seventeen thousand, eight hundred twenty-one".