401221711566 has 96 divisors (see below), whose sum is σ = 979843318272. Its totient is φ = 117728043840.

The previous prime is 401221711531. The next prime is 401221711577. The reversal of 401221711566 is 665117122104.

401221711566 is a `hidden beast` number, since 4 + 0 + 1 + 2 + 21 + 71 + 1 + 566 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 401221711566.

It is a congruent number.

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, 1668831 + ... + 1894053.

It is an arithmetic number, because the mean of its divisors is an integer number (10206701232).

Almost surely, 2^401221711566 is an apocalyptic number.

401221711566 is a gapful number since it is divisible by the number (46) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 401221711566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (489921659136).

401221711566 is an abundant number, since it is smaller than the sum of its proper divisors (578621606706).

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

401221711566 is a wasteful number, since it uses less digits than its factorization.

401221711566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225598 (or 225595 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 401221711566 in words is "four hundred one billion, two hundred twenty-one million, seven hundred eleven thousand, five hundred sixty-six".