1221610 has 16 divisors (see below), whose sum is σ = 2368296. Its totient is φ = 451008.

The previous prime is 1221601. The next prime is 1221631. The reversal of 1221610 is 161221.

It can be written as a sum of positive squares in 4 ways, for example, as 339889 + 881721 = 583^2 + 939^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4569 + ... + 4828.

2^1221610 is an apocalyptic number.

1221610 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221610 is a deficient number, since it is larger than the sum of its proper divisors (1146686).

1221610 is a wasteful number, since it uses less digits than its factorization.

1221610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9417.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1221610 is about 1105.2646741844. The cubic root of 1221610 is about 106.8999559838.

Adding to 1221610 its reverse (161221), we get a palindrome (1382831).

It can be divided in two parts, 1221 and 610, that multiplied together give a triangular number (744810 = T₁₂₂₀).

The spelling of 1221610 in words is "one million, two hundred twenty-one thousand, six hundred ten".