1021219979 has 4 divisors (see below), whose sum is σ = 1099775376. Its totient is φ = 942664584.

The previous prime is 1021219957. The next prime is 1021220021. The reversal of 1021219979 is 9799121201.

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 1021219979 - 2⁸ = 1021219723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021219379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39277679 + ... + 39277704.

It is an arithmetic number, because the mean of its divisors is an integer number (274943844).

Almost surely, 2^1021219979 is an apocalyptic number.

1021219979 is a deficient number, since it is larger than the sum of its proper divisors (78555397).

1021219979 is an equidigital number, since it uses as much as digits as its factorization.

1021219979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78555396.

The product of its (nonzero) digits is 20412, while the sum is 41.

The square root of 1021219979 is about 31956.5326498355. The cubic root of 1021219979 is about 1007.0238759921.

The spelling of 1021219979 in words is "one billion, twenty-one million, two hundred nineteen thousand, nine hundred seventy-nine".