1221730 has 8 divisors (see below), whose sum is σ = 2199132. Its totient is φ = 488688.

The previous prime is 1221707. The next prime is 1221749. The reversal of 1221730 is 371221.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1172889 + 48841 = 1083^2 + 221^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61077 + ... + 61096.

2^1221730 is an apocalyptic number.

1221730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221730 is a deficient number, since it is larger than the sum of its proper divisors (977402).

1221730 is a wasteful number, since it uses less digits than its factorization.

1221730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122180.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 1221730 is about 1105.3189584912. The cubic root of 1221730 is about 106.9034561665.

Adding to 1221730 its reverse (371221), we get a palindrome (1592951).

The spelling of 1221730 in words is "one million, two hundred twenty-one thousand, seven hundred thirty".