1221975 has 18 divisors (see below), whose sum is σ = 2189096. Its totient is φ = 651600.

The previous prime is 1221971. The next prime is 1222003. The reversal of 1221975 is 5791221.

It is not a de Polignac number, because 1221975 - 2² = 1221971 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 (1221971) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 2491 + ... + 2940.

2^1221975 is an apocalyptic number.

1221975 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1221975 is a deficient number, since it is larger than the sum of its proper divisors (967121).

1221975 is a wasteful number, since it uses less digits than its factorization.

1221975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5447 (or 5439 counting only the distinct ones).

The product of its digits is 1260, while the sum is 27.

The square root of 1221975 is about 1105.4297806736. The cubic root of 1221975 is about 106.9106016613.

The spelling of 1221975 in words is "one million, two hundred twenty-one thousand, nine hundred seventy-five".