10861221 has 32 divisors (see below), whose sum is σ = 17510400. Its totient is φ = 5854464.

The previous prime is 10861219. The next prime is 10861243. The reversal of 10861221 is 12216801.

10861221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 10861221 - 2¹ = 10861219 is a prime.

It is a super-2 number, since 2×10861221² = 235932243221682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10861211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54480 + ... + 54678.

It is an arithmetic number, because the mean of its divisors is an integer number (547200).

Almost surely, 2^10861221 is an apocalyptic number.

It is an amenable number.

10861221 is a deficient number, since it is larger than the sum of its proper divisors (6649179).

10861221 is a wasteful number, since it uses less digits than its factorization.

10861221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 10861221 is about 3295.6366607986. The cubic root of 10861221 is about 221.4587700352.

It can be divided in two parts, 1086 and 1221, that multiplied together give a triangular number (1326006 = T₁₆₂₈).

The spelling of 10861221 in words is "ten million, eight hundred sixty-one thousand, two hundred twenty-one".