2221571664 has 160 divisors (see below), whose sum is σ = 6933306240. Its totient is φ = 676988928.

The previous prime is 2221571657. The next prime is 2221571687. The reversal of 2221571664 is 4661751222.

It is a happy number.

2221571664 is a `hidden beast` number, since 2 + 2 + 21 + 571 + 6 + 64 = 666.

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 31 ways as a sum of consecutive naturals, for example, 599064 + ... + 602760.

It is an arithmetic number, because the mean of its divisors is an integer number (43333164).

Almost surely, 2^2221571664 is an apocalyptic number.

2221571664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2221571664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3466653120).

2221571664 is an abundant number, since it is smaller than the sum of its proper divisors (4711734576).

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

2221571664 is a wasteful number, since it uses less digits than its factorization.

2221571664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3834 (or 3822 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 2221571664 is about 47133.5513620606. The cubic root of 2221571664 is about 1304.8285254944.

The spelling of 2221571664 in words is "two billion, two hundred twenty-one million, five hundred seventy-one thousand, six hundred sixty-four".