1220778379 has 4 divisors (see below), whose sum is σ = 1234495080. Its totient is φ = 1207061680.

The previous prime is 1220778373. The next prime is 1220778397. The reversal of 1220778379 is 9738770221.

It is a happy number.

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 1220778379 - 2³ = 1220778371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1220778371) 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, 6858217 + ... + 6858394.

It is an arithmetic number, because the mean of its divisors is an integer number (308623770).

Almost surely, 2^1220778379 is an apocalyptic number.

1220778379 is a deficient number, since it is larger than the sum of its proper divisors (13716701).

1220778379 is an equidigital number, since it uses as much as digits as its factorization.

1220778379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13716700.

The product of its (nonzero) digits is 296352, while the sum is 46.

The square root of 1220778379 is about 34939.6390794181. The cubic root of 1220778379 is about 1068.7569280401.

The spelling of 1220778379 in words is "one billion, two hundred twenty million, seven hundred seventy-eight thousand, three hundred seventy-nine".