1221496979 has 4 divisors (see below), whose sum is σ = 1221821976. Its totient is φ = 1221171984.

The previous prime is 1221496967. The next prime is 1221496981. The reversal of 1221496979 is 9796941221.

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 1221496979 - 2⁴ = 1221496963 is a prime.

It is a super-2 number, since 2×1221496979² = 2984109739412252882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221490979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156794 + ... + 164399.

It is an arithmetic number, because the mean of its divisors is an integer number (305455494).

Almost surely, 2^1221496979 is an apocalyptic number.

1221496979 is a deficient number, since it is larger than the sum of its proper divisors (324997).

1221496979 is an equidigital number, since it uses as much as digits as its factorization.

1221496979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324996.

The product of its digits is 489888, while the sum is 50.

The square root of 1221496979 is about 34949.9210156475. The cubic root of 1221496979 is about 1068.9665915622.

The spelling of 1221496979 in words is "one billion, two hundred twenty-one million, four hundred ninety-six thousand, nine hundred seventy-nine".