1211421979 has 2 divisors, whose sum is σ = 1211421980. Its totient is φ = 1211421978.

The previous prime is 1211421973. The next prime is 1211422019. The reversal of 1211421979 is 9791241121.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1211421979 - 2⁹ = 1211421467 is a prime.

It is a super-3 number, since 3×1211421979³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1211421973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605710989 + 605710990.

It is an arithmetic number, because the mean of its divisors is an integer number (605710990).

Almost surely, 2^1211421979 is an apocalyptic number.

1211421979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211421979 is an equidigital number, since it uses as much as digits as its factorization.

1211421979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 37.

The square root of 1211421979 is about 34805.4877713271. The cubic root of 1211421979 is about 1066.0195014543.

The spelling of 1211421979 in words is "one billion, two hundred eleven million, four hundred twenty-one thousand, nine hundred seventy-nine".