220261861 has 4 divisors (see below), whose sum is σ = 220291852. Its totient is φ = 220231872.

The previous prime is 220261849. The next prime is 220261879. The reversal of 220261861 is 168162022.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 18792225 + 201469636 = 4335^2 + 14194^2 .

It is a 3-Lehmer number, since φ(220261861) divides (220261861-1)³.

It is a cyclic number.

It is not a de Polignac number, because 220261861 - 2¹³ = 220253669 is a prime.

It is a super-2 number, since 2×220261861² = 97030574822366642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220261801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4285 + ... + 21421.

It is an arithmetic number, because the mean of its divisors is an integer number (55072963).

It is a Poulet number, since it divides 2^220261860-1.

Almost surely, 2^220261861 is an apocalyptic number.

It is an amenable number.

220261861 is a deficient number, since it is larger than the sum of its proper divisors (29991).

220261861 is a wasteful number, since it uses less digits than its factorization.

220261861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29990.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 220261861 is about 14841.2216815193. The cubic root of 220261861 is about 603.9204946664.

It can be divided in two parts, 220261 and 861, that added together give a palindrome (221122).

The spelling of 220261861 in words is "two hundred twenty million, two hundred sixty-one thousand, eight hundred sixty-one".