2211780661 has 8 divisors (see below), whose sum is σ = 2270315520. Its totient is φ = 2153724048.

The previous prime is 2211780643. The next prime is 2211780667. The reversal of 2211780661 is 1660871122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2211780661 - 2¹⁵ = 2211747893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2211780667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110181 + ... + 128698.

It is an arithmetic number, because the mean of its divisors is an integer number (283789440).

Almost surely, 2^2211780661 is an apocalyptic number.

It is an amenable number.

2211780661 is a deficient number, since it is larger than the sum of its proper divisors (58534859).

2211780661 is a wasteful number, since it uses less digits than its factorization.

2211780661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239123.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 2211780661 is about 47029.5721966509. The cubic root of 2211780661 is about 1302.9088043258.

The spelling of 2211780661 in words is "two billion, two hundred eleven million, seven hundred eighty thousand, six hundred sixty-one".