1221977 has 4 divisors (see below), whose sum is σ = 1293876. Its totient is φ = 1150080.

The previous prime is 1221971. The next prime is 1222003. The reversal of 1221977 is 7791221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7791221 = 1433 ⋅5437.

It can be written as a sum of positive squares in 2 ways, for example, as 355216 + 866761 = 596^2 + 931^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221977 - 2¹⁰ = 1220953 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221971) 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, 35924 + ... + 35957.

It is an arithmetic number, because the mean of its divisors is an integer number (323469).

2^1221977 is an apocalyptic number.

1221977 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1221977 is a deficient number, since it is larger than the sum of its proper divisors (71899).

1221977 is an equidigital number, since it uses as much as digits as its factorization.

1221977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71898.

The product of its digits is 1764, while the sum is 29.

The square root of 1221977 is about 1105.4306852987. The cubic root of 1221977 is about 106.9106599880.

The spelling of 1221977 in words is "one million, two hundred twenty-one thousand, nine hundred seventy-seven".