1221379 has 2 divisors, whose sum is σ = 1221380. Its totient is φ = 1221378.

The previous prime is 1221373. The next prime is 1221383. The reversal of 1221379 is 9731221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221379 - 2⁷ = 1221251 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610689 + 610690.

It is an arithmetic number, because the mean of its divisors is an integer number (610690).

2^1221379 is an apocalyptic number.

1221379 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221379 is an equidigital number, since it uses as much as digits as its factorization.

1221379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 25.

The square root of 1221379 is about 1105.1601693872. The cubic root of 1221379 is about 106.8932174866.

It can be divided in two parts, 1221 and 379, that added together give a square (1600 = 40²).

The spelling of 1221379 in words is "one million, two hundred twenty-one thousand, three hundred seventy-nine".