401817780 has 576 divisors, whose sum is σ = 1682311680. Its totient is φ = 77635584.

The previous prime is 401817761. The next prime is 401817799. The reversal of 401817780 is 87718104.

401817780 is a `hidden beast` number, since 401 + 8 + 177 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (401817761) and next prime (401817799).

It is a super-2 number, since 2×401817780² = 322915056648256800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 10859922 + ... + 10859958.

It is an arithmetic number, because the mean of its divisors is an integer number (2920680).

Almost surely, 2^401817780 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 401817780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (841155840).

401817780 is an abundant number, since it is smaller than the sum of its proper divisors (1280493900).

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

401817780 is a wasteful number, since it uses less digits than its factorization.

401817780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 401817780 is about 20045.3929869185. The cubic root of 401817780 is about 737.9207397197.

It can be divided in two parts, 40181 and 7780, that added together give a square (47961 = 219²).

The spelling of 401817780 in words is "four hundred one million, eight hundred seventeen thousand, seven hundred eighty".