1221963 has 4 divisors (see below), whose sum is σ = 1629288. Its totient is φ = 814640.

The previous prime is 1221959. The next prime is 1221971. The reversal of 1221963 is 3691221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221963 - 2² = 1221959 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1221163) 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, 203658 + ... + 203663.

It is an arithmetic number, because the mean of its divisors is an integer number (407322).

2^1221963 is an apocalyptic number.

1221963 is a deficient number, since it is larger than the sum of its proper divisors (407325).

1221963 is an equidigital number, since it uses as much as digits as its factorization.

1221963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407324.

The product of its digits is 648, while the sum is 24.

The square root of 1221963 is about 1105.4243529071. The cubic root of 1221963 is about 106.9102517002.

The spelling of 1221963 in words is "one million, two hundred twenty-one thousand, nine hundred sixty-three".